<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <link:roleRef roleURI="http://www.fortinet.com/role/AccumulatedOtherComprehensiveLoss" xlink:href="ftnt-20171231.xsd#AccumulatedOtherComprehensiveLoss" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/AccumulatedOtherComprehensiveLossChangesInAccumulatedBalancesOfOtherComprehensiveLossDetails" xlink:href="ftnt-20171231.xsd#AccumulatedOtherComprehensiveLossChangesInAccumulatedBalancesOfOtherComprehensiveLossDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/AccumulatedOtherComprehensiveLossTables" xlink:href="ftnt-20171231.xsd#AccumulatedOtherComprehensiveLossTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/BusinessCombinations" xlink:href="ftnt-20171231.xsd#BusinessCombinations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/BusinessCombinationsAdditionalInformationDetails" xlink:href="ftnt-20171231.xsd#BusinessCombinationsAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/BusinessCombinationsIntangibleAssetsAcquiredDetails" xlink:href="ftnt-20171231.xsd#BusinessCombinationsIntangibleAssetsAcquiredDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/BusinessCombinationsPurchasePriceAllocationsDetails" xlink:href="ftnt-20171231.xsd#BusinessCombinationsPurchasePriceAllocationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/BusinessCombinationsTables" xlink:href="ftnt-20171231.xsd#BusinessCombinationsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/CommitmentsAndContingencies" xlink:href="ftnt-20171231.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/CommitmentsAndContingenciesDetails" xlink:href="ftnt-20171231.xsd#CommitmentsAndContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/CommitmentsAndContingenciesMinimumOperatingLeasePaymentsDetails" xlink:href="ftnt-20171231.xsd#CommitmentsAndContingenciesMinimumOperatingLeasePaymentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/CommitmentsAndContingenciesTables" xlink:href="ftnt-20171231.xsd#CommitmentsAndContingenciesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/ConsolidatedBalanceSheets" xlink:href="ftnt-20171231.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:href="ftnt-20171231.xsd#ConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="ftnt-20171231.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:href="ftnt-20171231.xsd#ConsolidatedStatementsOfComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/ConsolidatedStatementsOfOperations" xlink:href="ftnt-20171231.xsd#ConsolidatedStatementsOfOperations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:href="ftnt-20171231.xsd#ConsolidatedStatementsOfStockholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/DefinedContributionPlans" xlink:href="ftnt-20171231.xsd#DefinedContributionPlans" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/DefinedContributionPlansDetails" xlink:href="ftnt-20171231.xsd#DefinedContributionPlansDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/DocumentAndEntityInformation" xlink:href="ftnt-20171231.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/FinancialInstrumentsAndFairValue" xlink:href="ftnt-20171231.xsd#FinancialInstrumentsAndFairValue" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/FinancialInstrumentsAndFairValueAdditionalInformationDetails" xlink:href="ftnt-20171231.xsd#FinancialInstrumentsAndFairValueAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/FinancialInstrumentsAndFairValueFairValueMeasurementsDetails" xlink:href="ftnt-20171231.xsd#FinancialInstrumentsAndFairValueFairValueMeasurementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/FinancialInstrumentsAndFairValueInvestmentsDetails" xlink:href="ftnt-20171231.xsd#FinancialInstrumentsAndFairValueInvestmentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/FinancialInstrumentsAndFairValueTables" xlink:href="ftnt-20171231.xsd#FinancialInstrumentsAndFairValueTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNet" xlink:href="ftnt-20171231.xsd#GoodwillAndOtherIntangibleAssetsNet" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNetEstimatedFutureAmortizationExpenseDetails" xlink:href="ftnt-20171231.xsd#GoodwillAndOtherIntangibleAssetsNetEstimatedFutureAmortizationExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNetGoodwillDetails" xlink:href="ftnt-20171231.xsd#GoodwillAndOtherIntangibleAssetsNetGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNetOtherIntangibleAssetsNetDetails" xlink:href="ftnt-20171231.xsd#GoodwillAndOtherIntangibleAssetsNetOtherIntangibleAssetsNetDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNetTables" xlink:href="ftnt-20171231.xsd#GoodwillAndOtherIntangibleAssetsNetTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/IncomeTaxes" xlink:href="ftnt-20171231.xsd#IncomeTaxes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/IncomeTaxesDeferredTaxAssetsDetails" xlink:href="ftnt-20171231.xsd#IncomeTaxesDeferredTaxAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/IncomeTaxesEffectiveTaxRateReconciliationDetails" xlink:href="ftnt-20171231.xsd#IncomeTaxesEffectiveTaxRateReconciliationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/IncomeTaxesProvisionForIncomeTaxDetails" xlink:href="ftnt-20171231.xsd#IncomeTaxesProvisionForIncomeTaxDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/IncomeTaxesReconciliationOfPreTaxIncomedetails" xlink:href="ftnt-20171231.xsd#IncomeTaxesReconciliationOfPreTaxIncomedetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/IncomeTaxesTables" xlink:href="ftnt-20171231.xsd#IncomeTaxesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/IncomeTaxesTcjaNarrativeDetails" xlink:href="ftnt-20171231.xsd#IncomeTaxesTcjaNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:href="ftnt-20171231.xsd#IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/Inventory" xlink:href="ftnt-20171231.xsd#Inventory" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/InventoryDetails" xlink:href="ftnt-20171231.xsd#InventoryDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/InventoryTables" xlink:href="ftnt-20171231.xsd#InventoryTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/InvestmentsInPrivatelyHeldCompanies" xlink:href="ftnt-20171231.xsd#InvestmentsInPrivatelyHeldCompanies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/InvestmentsInPrivatelyHeldCompaniesDetails" xlink:href="ftnt-20171231.xsd#InvestmentsInPrivatelyHeldCompaniesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/NetIncomePerShare" xlink:href="ftnt-20171231.xsd#NetIncomePerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/NetIncomePerShareAntiDilutiveSecuritiesDetails" xlink:href="ftnt-20171231.xsd#NetIncomePerShareAntiDilutiveSecuritiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/NetIncomePerShareCalculationOfBasicAndDilutedDetails" xlink:href="ftnt-20171231.xsd#NetIncomePerShareCalculationOfBasicAndDilutedDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/NetIncomePerShareTables" xlink:href="ftnt-20171231.xsd#NetIncomePerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/PropertyAndEquipmentnet" xlink:href="ftnt-20171231.xsd#PropertyAndEquipmentnet" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/PropertyAndEquipmentnetDetails" xlink:href="ftnt-20171231.xsd#PropertyAndEquipmentnetDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/PropertyAndEquipmentnetTables" xlink:href="ftnt-20171231.xsd#PropertyAndEquipmentnetTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/RelatedPartyTransactions" xlink:href="ftnt-20171231.xsd#RelatedPartyTransactions" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/RelatedPartyTransactionsDetails" xlink:href="ftnt-20171231.xsd#RelatedPartyTransactionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/RestructuringCharges" xlink:href="ftnt-20171231.xsd#RestructuringCharges" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/RestructuringChargesAdditionalInformationDetails" xlink:href="ftnt-20171231.xsd#RestructuringChargesAdditionalInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/RestructuringChargesRestructuringActivityDetails" xlink:href="ftnt-20171231.xsd#RestructuringChargesRestructuringActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/RestructuringChargesTables" xlink:href="ftnt-20171231.xsd#RestructuringChargesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/ScheduleIiValuationAndQualifyingAccounts" xlink:href="ftnt-20171231.xsd#ScheduleIiValuationAndQualifyingAccounts" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/ScheduleIiValuationAndQualifyingAccountsDetails" xlink:href="ftnt-20171231.xsd#ScheduleIiValuationAndQualifyingAccountsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SegmentInformation" xlink:href="ftnt-20171231.xsd#SegmentInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SegmentInformationDetails" xlink:href="ftnt-20171231.xsd#SegmentInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SegmentInformationTables" xlink:href="ftnt-20171231.xsd#SegmentInformationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquity" xlink:href="ftnt-20171231.xsd#StockholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityAdditionalInformationRelatedToEsppDetails" xlink:href="ftnt-20171231.xsd#StockholdersEquityAdditionalInformationRelatedToEsppDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityAllocationOfStockBasedCompensationExpenseDetails" xlink:href="ftnt-20171231.xsd#StockholdersEquityAllocationOfStockBasedCompensationExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityDetails" xlink:href="ftnt-20171231.xsd#StockholdersEquityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityEsppInformationDetails" xlink:href="ftnt-20171231.xsd#StockholdersEquityEsppInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityPerformanceStockUnitsDetails" xlink:href="ftnt-20171231.xsd#StockholdersEquityPerformanceStockUnitsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityRangeOfOptionsDetails" xlink:href="ftnt-20171231.xsd#StockholdersEquityRangeOfOptionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityRestrictedStockUnitsActivityDetails" xlink:href="ftnt-20171231.xsd#StockholdersEquityRestrictedStockUnitsActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityShareRepurchaseProgramDetails" xlink:href="ftnt-20171231.xsd#StockholdersEquityShareRepurchaseProgramDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/StockholdersEquityTables" xlink:href="ftnt-20171231.xsd#StockholdersEquityTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPolicies" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesAccountsReceivableDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesAccountsReceivableDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesCashCashEquivalentsAndAvailableForSaleInvestmentsDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesCashCashEquivalentsAndAvailableForSaleInvestmentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesConcentrationOfCreditRiskDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesConcentrationOfCreditRiskDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesDerivativesDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesDerivativesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesForeignCurrencyTranslationDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesForeignCurrencyTranslationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesGoodwillDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesGoodwillDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesOtherIntangibleAssetsDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesOtherIntangibleAssetsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesRecentAccountingPronouncementsDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesRecentAccountingPronouncementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesRevenueRecognitionDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesRevenueRecognitionDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesStockBasedCompensationDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesStockBasedCompensationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesTables" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesWarrantiesDetails" xlink:href="ftnt-20171231.xsd#SummaryOfSignificantAccountingPoliciesWarrantiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedNetLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedNetLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedPeriodEndLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodEndLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedPeriodStartLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodStartLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTerseLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTotalLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/netLabel" xlink:href="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd#netLabel" xlink:type="simple" />
  <link:presentationLink xlink:role="http://www.fortinet.com/role/AccumulatedOtherComprehensiveLoss" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_6A8DE59F62544D848EC5BBEB9B7B1D7D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComprehensiveIncomeNoteTextBlock" xlink:label="loc_us-gaap_ComprehensiveIncomeNoteTextBlock_B51B5C4C6B178B1126BBBBEB9B7B2316" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_6A8DE59F62544D848EC5BBEB9B7B1D7D" xlink:to="loc_us-gaap_ComprehensiveIncomeNoteTextBlock_B51B5C4C6B178B1126BBBBEB9B7B2316" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/AccumulatedOtherComprehensiveLossChangesInAccumulatedBalancesOfOtherComprehensiveLossDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_4F25084A5C4ECE64A9BDBB5150F2608E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1A053ACB66362E1B5988BB5150F2C36E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_4F25084A5C4ECE64A9BDBB5150F2608E" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1A053ACB66362E1B5988BB5150F2C36E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_82C703B07D9E813C0AC7BB5150F304D6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1A053ACB66362E1B5988BB5150F2C36E" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_82C703B07D9E813C0AC7BB5150F304D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_1F3909F3C25BB140D172BB5150F354F1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_82C703B07D9E813C0AC7BB5150F304D6" xlink:to="loc_us-gaap_EquityComponentDomain_1F3909F3C25BB140D172BB5150F354F1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_DE2253D5A1F9742315D6BB5150F4A15A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityComponentDomain_1F3909F3C25BB140D172BB5150F354F1" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_DE2253D5A1F9742315D6BB5150F4A15A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_96309520EDE7B8CEBEE8BB5150F4DBB5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_1A053ACB66362E1B5988BB5150F2C36E" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_96309520EDE7B8CEBEE8BB5150F4DBB5" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AccumulatedOtherComprehensiveIncomeRollForward" xlink:label="loc_ftnt_AccumulatedOtherComprehensiveIncomeRollForward_D429F74975B1D2A5FC15BB5150F4B269" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_96309520EDE7B8CEBEE8BB5150F4DBB5" xlink:to="loc_ftnt_AccumulatedOtherComprehensiveIncomeRollForward_D429F74975B1D2A5FC15BB5150F4B269" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossBeforeTax1" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossBeforeTax1_E2E9C69270FA50461CE4BB5150F4E424" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeRollForward_D429F74975B1D2A5FC15BB5150F4B269" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossBeforeTax1_E2E9C69270FA50461CE4BB5150F4E424" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax_21C556024B8A79BE289EBB5150F411DD" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeRollForward_D429F74975B1D2A5FC15BB5150F4B269" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsBeforeTax_21C556024B8A79BE289EBB5150F411DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_7E6F0770C39610511746BB5150F57B30" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeRollForward_D429F74975B1D2A5FC15BB5150F4B269" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax_7E6F0770C39610511746BB5150F57B30" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_B7CB0AC66E8E61747E85BB5150F59900" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeRollForward_D429F74975B1D2A5FC15BB5150F4B269" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_B7CB0AC66E8E61747E85BB5150F59900" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossBeforeTax1" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossBeforeTax1_E4269092DAE05B671784BB5150F6A025" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeRollForward_D429F74975B1D2A5FC15BB5150F4B269" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossBeforeTax1_E4269092DAE05B671784BB5150F6A025" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AccumulatedOtherComprehensiveIncomeTaxRollForward" xlink:label="loc_ftnt_AccumulatedOtherComprehensiveIncomeTaxRollForward_BA1B9203A88BAAF4CDCABB5150F629E5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_96309520EDE7B8CEBEE8BB5150F4DBB5" xlink:to="loc_ftnt_AccumulatedOtherComprehensiveIncomeTaxRollForward_BA1B9203A88BAAF4CDCABB5150F629E5" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AccumulatedOtherComprehensiveIncomeLossTax" xlink:label="loc_ftnt_AccumulatedOtherComprehensiveIncomeLossTax_5E8EA3EA3B477274B385BB5150F635E1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeTaxRollForward_BA1B9203A88BAAF4CDCABB5150F629E5" xlink:to="loc_ftnt_AccumulatedOtherComprehensiveIncomeLossTax_5E8EA3EA3B477274B385BB5150F635E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_60AACB07420FAEAA26FEBB5150F6A17E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeTaxRollForward_BA1B9203A88BAAF4CDCABB5150F629E5" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax_60AACB07420FAEAA26FEBB5150F6A17E" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ReclassificationfromAccumulatedOtherComprehensiveIncomeCurrentPeriodTax" xlink:label="loc_ftnt_ReclassificationfromAccumulatedOtherComprehensiveIncomeCurrentPeriodTax_72476972107FD85C42A0BB5150F6797C" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeTaxRollForward_BA1B9203A88BAAF4CDCABB5150F629E5" xlink:to="loc_ftnt_ReclassificationfromAccumulatedOtherComprehensiveIncomeCurrentPeriodTax_72476972107FD85C42A0BB5150F6797C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_481B1618718B74994448BB5150F6E464" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeTaxRollForward_BA1B9203A88BAAF4CDCABB5150F629E5" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_481B1618718B74994448BB5150F6E464" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AccumulatedOtherComprehensiveIncomeLossTax" xlink:label="loc_ftnt_AccumulatedOtherComprehensiveIncomeLossTax_7DEA62721E204F33CDA1BB5150F70549" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_AccumulatedOtherComprehensiveIncomeTaxRollForward_BA1B9203A88BAAF4CDCABB5150F629E5" xlink:to="loc_ftnt_AccumulatedOtherComprehensiveIncomeLossTax_7DEA62721E204F33CDA1BB5150F70549" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/AccumulatedOtherComprehensiveLossTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_93C56B456DBCB52011A6BBEB9BAF1D89" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock_6EE5E59E200D0C86E6E9BBEB9BAF353A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_93C56B456DBCB52011A6BBEB9BAF1D89" xlink:to="loc_us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock_6EE5E59E200D0C86E6E9BBEB9BAF353A" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/BusinessCombinations" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="loc_us-gaap_BusinessCombinationsAbstract_108F966BFAD36BE958FFB9809C610FFE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationDisclosureTextBlock" xlink:label="loc_us-gaap_BusinessCombinationDisclosureTextBlock_BB778973CF071F71318FB9809C61204F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessCombinationsAbstract_108F966BFAD36BE958FFB9809C610FFE" xlink:to="loc_us-gaap_BusinessCombinationDisclosureTextBlock_BB778973CF071F71318FB9809C61204F" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/BusinessCombinationsAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="loc_us-gaap_BusinessCombinationsAbstract_1A418DED1871ECB3D5A7B5D762F92212" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_112CCF4C416DF4E91A06B5D762F94DBF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessCombinationsAbstract_1A418DED1871ECB3D5A7B5D762F92212" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_112CCF4C416DF4E91A06B5D762F94DBF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_BAA856671E6955204B94B5D762FA6E8D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_112CCF4C416DF4E91A06B5D762F94DBF" xlink:to="loc_us-gaap_AwardTypeAxis_BAA856671E6955204B94B5D762FA6E8D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6C0CF540FB9408560C87B5D762FA30F9" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_BAA856671E6955204B94B5D762FA6E8D" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6C0CF540FB9408560C87B5D762FA30F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_CECE61DAF39D6461297EB5D762FFB606" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_6C0CF540FB9408560C87B5D762FA30F9" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_CECE61DAF39D6461297EB5D762FFB606" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_C40CC51B4F7B5C9A4331B5D7630094A3" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_112CCF4C416DF4E91A06B5D762F94DBF" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_C40CC51B4F7B5C9A4331B5D7630094A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1F2D3AC96BB751B31066B5D76300E087" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_C40CC51B4F7B5C9A4331B5D7630094A3" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1F2D3AC96BB751B31066B5D76300E087" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AccelOpsInc.Member" xlink:label="loc_ftnt_AccelOpsInc.Member_3A2AEE2C460BE57C399FB5D76300CE13" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1F2D3AC96BB751B31066B5D76300E087" xlink:to="loc_ftnt_AccelOpsInc.Member_3A2AEE2C460BE57C399FB5D76300CE13" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_MeruNetworksInc.Member" xlink:label="loc_ftnt_MeruNetworksInc.Member_5D7755155E6660D1DAFFB5D76300ED08" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1F2D3AC96BB751B31066B5D76300E087" xlink:to="loc_ftnt_MeruNetworksInc.Member_5D7755155E6660D1DAFFB5D76300ED08" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_112CCF4C416DF4E91A06B5D762F94DBF" xlink:to="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_195426E2D83AA4AEDE4DB5D7630068A3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_195426E2D83AA4AEDE4DB5D7630068A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_0A2E665D6A30D7A20848B5D763003575" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:to="loc_us-gaap_Goodwill_0A2E665D6A30D7A20848B5D763003575" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_9D3F451CA55148FCD9A1B5DEA31AAA8C" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_9D3F451CA55148FCD9A1B5DEA31AAA8C" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_BusinessCombinationConsiderationTransferredEstimatedFairValueofSharesWithheldforTaxes" xlink:label="loc_ftnt_BusinessCombinationConsiderationTransferredEstimatedFairValueofSharesWithheldforTaxes_1937AA83FB9382E6E31AB5D76300B860" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:to="loc_ftnt_BusinessCombinationConsiderationTransferredEstimatedFairValueofSharesWithheldforTaxes_1937AA83FB9382E6E31AB5D76300B860" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_FF3139B52A8EC49CE042B5D763007C3F" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_FF3139B52A8EC49CE042B5D763007C3F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_8BFB88425102E5B1DECEB5D763014005" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_8BFB88425102E5B1DECEB5D763014005" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_8E23B04F7B1A10BB049DB5D7630133E7" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_18C505D0D617E6B2E9D0B5D76300AD3C" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_8E23B04F7B1A10BB049DB5D7630133E7" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/BusinessCombinationsIntangibleAssetsAcquiredDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="loc_us-gaap_BusinessCombinationsAbstract_B9B7C62625846C2FD5DBB596A11F8B0F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3914F7CA198A2A65FF51B596A120002C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessCombinationsAbstract_B9B7C62625846C2FD5DBB596A11F8B0F" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3914F7CA198A2A65FF51B596A120002C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F58BC10DFC6DD45A8F5FB596A12094A3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3914F7CA198A2A65FF51B596A120002C" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F58BC10DFC6DD45A8F5FB596A12094A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_274B983B8A667B7F218AB596A120ADF2" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F58BC10DFC6DD45A8F5FB596A12094A3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_274B983B8A667B7F218AB596A120ADF2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TechnologyBasedIntangibleAssetsMember" xlink:label="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_80D3B2D560F230BB379CB596A1204F3E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_274B983B8A667B7F218AB596A120ADF2" xlink:to="loc_us-gaap_TechnologyBasedIntangibleAssetsMember_80D3B2D560F230BB379CB596A1204F3E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_D3DF7FB54935D4D597B3B596A125C515" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_274B983B8A667B7F218AB596A120ADF2" xlink:to="loc_us-gaap_CustomerRelationshipsMember_D3DF7FB54935D4D597B3B596A125C515" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherIntangibleAssetsMember" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_7015D84450D8EC961BF6B596A12589E8" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_274B983B8A667B7F218AB596A120ADF2" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_7015D84450D8EC961BF6B596A12589E8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember_62CA5785E62D9C802132B596A1250854" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_274B983B8A667B7F218AB596A120ADF2" xlink:to="loc_us-gaap_TradeNamesMember_62CA5785E62D9C802132B596A1250854" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_7DDF8A407803228E594EB596A1258708" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3914F7CA198A2A65FF51B596A120002C" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_7DDF8A407803228E594EB596A1258708" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC063D3DD27C9DED409AB596A12589D2" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_7DDF8A407803228E594EB596A1258708" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC063D3DD27C9DED409AB596A12589D2" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AccelOpsInc.Member" xlink:label="loc_ftnt_AccelOpsInc.Member_B80CA697D34AA8444387B596A12656DB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC063D3DD27C9DED409AB596A12589D2" xlink:to="loc_ftnt_AccelOpsInc.Member_B80CA697D34AA8444387B596A12656DB" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_MeruNetworksInc.Member" xlink:label="loc_ftnt_MeruNetworksInc.Member_54368782CEBAAC87CAD9B596A126E37A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_EC063D3DD27C9DED409AB596A12589D2" xlink:to="loc_ftnt_MeruNetworksInc.Member_54368782CEBAAC87CAD9B596A126E37A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_04506A13D02F4D2E57D0B596A1269BC6" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_3914F7CA198A2A65FF51B596A120002C" xlink:to="loc_us-gaap_BusinessAcquisitionLineItems_04506A13D02F4D2E57D0B596A1269BC6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_5CB3699D8BDAEDABBA95B596A1264399" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_04506A13D02F4D2E57D0B596A1269BC6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_5CB3699D8BDAEDABBA95B596A1264399" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_E6F9ECCA285FE6D7C5B6B596A1268E7A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_04506A13D02F4D2E57D0B596A1269BC6" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_E6F9ECCA285FE6D7C5B6B596A1268E7A" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/BusinessCombinationsPurchasePriceAllocationsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="loc_us-gaap_BusinessCombinationsAbstract_17E9BEE5FB03AB7FE5D6B9809C31B09F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_89F76D79578F522F6A34B9809C310BBB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessCombinationsAbstract_17E9BEE5FB03AB7FE5D6B9809C31B09F" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_89F76D79578F522F6A34B9809C310BBB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_74EA8C0B7919C6C9F534B9809C31469B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_89F76D79578F522F6A34B9809C310BBB" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_74EA8C0B7919C6C9F534B9809C31469B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_CB92C78CE8C0A808FEE7B9809C319A24" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_74EA8C0B7919C6C9F534B9809C31469B" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_CB92C78CE8C0A808FEE7B9809C319A24" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9FBA3C7659863CF13909B9809C315197" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_89F76D79578F522F6A34B9809C310BBB" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9FBA3C7659863CF13909B9809C315197" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_4E772F77B9D1495A8352B9809C31A673" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9FBA3C7659863CF13909B9809C315197" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_4E772F77B9D1495A8352B9809C31A673" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_E4B6477671C949EEF662B9809C32FBAD" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_89F76D79578F522F6A34B9809C310BBB" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_E4B6477671C949EEF662B9809C32FBAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E3EEDB9FD91ACB696D8DB9809C320E1E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_E4B6477671C949EEF662B9809C32FBAD" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E3EEDB9FD91ACB696D8DB9809C320E1E" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AccelOpsInc.Member" xlink:label="loc_ftnt_AccelOpsInc.Member_E85C5C9AF3E8DC5B5F70B9809C32BBCB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E3EEDB9FD91ACB696D8DB9809C320E1E" xlink:to="loc_ftnt_AccelOpsInc.Member_E85C5C9AF3E8DC5B5F70B9809C32BBCB" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_MeruNetworksInc.Member" xlink:label="loc_ftnt_MeruNetworksInc.Member_5E9D7B96FF422361FC8AB9809C32549C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_E3EEDB9FD91ACB696D8DB9809C320E1E" xlink:to="loc_ftnt_MeruNetworksInc.Member_5E9D7B96FF422361FC8AB9809C32549C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_89F76D79578F522F6A34B9809C310BBB" xlink:to="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_B8F73EE64FD5541021A3B9809C32F35D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_B8F73EE64FD5541021A3B9809C32F35D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_9C7EFD04A72815765F90B9809C325A8E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_9C7EFD04A72815765F90B9809C325A8E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_74B252921D8E57D4EC62B9809C320FB5" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_74B252921D8E57D4EC62B9809C320FB5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_78B2530FFD5AEBA588A5B9809C3294FD" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsPrepaidExpenseAndOtherAssets_78B2530FFD5AEBA588A5B9809C3294FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_42498A32629A476C6D7AB9809C320A0F" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_42498A32629A476C6D7AB9809C320A0F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssetsNoncurrent" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssetsNoncurrent_E734454C2E7AE738637FB9809C32CDA9" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssetsNoncurrent_E734454C2E7AE738637FB9809C32CDA9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_69B0C012974EDCDBDF83B9809C327719" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_69B0C012974EDCDBDF83B9809C327719" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_0FD9CDDBFD913E1941FDB9809C32EF05" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIndefiniteLivedIntangibleAssets_0FD9CDDBFD913E1941FDB9809C32EF05" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_F95E34D0B4C6B8A22A2DB9809C337B9B" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_Goodwill_F95E34D0B4C6B8A22A2DB9809C337B9B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_12AEF7814D63281B0DE9B9809C3366EA" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_12AEF7814D63281B0DE9B9809C3366EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_7982CF8DE7B456E450C5B9809C38E584" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesDeferredRevenue_7982CF8DE7B456E450C5B9809C38E584" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_28BA73370C889073DA02B9809C38E8F0" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable_28BA73370C889073DA02B9809C38E8F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther_1A0754DBF03973A7F051B9809C383EEC" xlink:type="locator" />
    <link:presentationArc order="13" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOther_1A0754DBF03973A7F051B9809C383EEC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_FCCA09AE7EF31BA1F4D6B9809C3894BD" xlink:type="locator" />
    <link:presentationArc order="14" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_FCCA09AE7EF31BA1F4D6B9809C3894BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_AA2CB30A64D60EF3BC43B9809C389C36" xlink:type="locator" />
    <link:presentationArc order="15" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D0ACC5096EB9564F61DDB9809C327739" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet_AA2CB30A64D60EF3BC43B9809C389C36" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/BusinessCombinationsTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:label="loc_us-gaap_BusinessCombinationsAbstract_75E856A903B5930195EFB596A1598351" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_A812E7A23282D4823F72B596A1598514" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessCombinationsAbstract_75E856A903B5930195EFB596A1598351" xlink:to="loc_us-gaap_ScheduleOfRecognizedIdentifiedAssetsAcquiredAndLiabilitiesAssumedTableTextBlock_A812E7A23282D4823F72B596A1598514" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_BA4F28F6C3DC5E11A0E6B596A159AC56" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessCombinationsAbstract_75E856A903B5930195EFB596A1598351" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock_BA4F28F6C3DC5E11A0E6B596A159AC56" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/CommitmentsAndContingencies" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_3E9F4CD3B8DCC14E63D9BBEB9C2501B6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_126A3DF7880932D73331BBEB9C255DF7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_3E9F4CD3B8DCC14E63D9BBEB9C2501B6" xlink:to="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_126A3DF7880932D73331BBEB9C255DF7" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/CommitmentsAndContingenciesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_6F9E9500390F130F1E12B9809BC8D8BB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesRentExpenseNet" xlink:label="loc_us-gaap_OperatingLeasesRentExpenseNet_CA1C657ECC9B2B713839B9809BC86B43" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_6F9E9500390F130F1E12B9809BC8D8BB" xlink:to="loc_us-gaap_OperatingLeasesRentExpenseNet_CA1C657ECC9B2B713839B9809BC86B43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligation" xlink:label="loc_us-gaap_PurchaseObligation_4EB4E7E20BBE672954A7B9809BC83000" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_6F9E9500390F130F1E12B9809BC8D8BB" xlink:to="loc_us-gaap_PurchaseObligation_4EB4E7E20BBE672954A7B9809BC83000" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherCommitment" xlink:label="loc_us-gaap_OtherCommitment_89BFBC59DE01F2574793B9809BC80969" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_6F9E9500390F130F1E12B9809BC8D8BB" xlink:to="loc_us-gaap_OtherCommitment_89BFBC59DE01F2574793B9809BC80969" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_A856818B62E7B0F649D7B9809BC8B79C" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_6F9E9500390F130F1E12B9809BC8D8BB" xlink:to="loc_us-gaap_LossContingenciesTable_A856818B62E7B0F649D7B9809BC8B79C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LitigationStatusAxis" xlink:label="loc_us-gaap_LitigationStatusAxis_06CB74329A2F0550FB7EB9809BC8E0C1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LossContingenciesTable_A856818B62E7B0F649D7B9809BC8B79C" xlink:to="loc_us-gaap_LitigationStatusAxis_06CB74329A2F0550FB7EB9809BC8E0C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LitigationStatusDomain" xlink:label="loc_us-gaap_LitigationStatusDomain_EE6CA47F1B237D03CEE4B9809BC828F0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LitigationStatusAxis_06CB74329A2F0550FB7EB9809BC8E0C1" xlink:to="loc_us-gaap_LitigationStatusDomain_EE6CA47F1B237D03CEE4B9809BC828F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SettledLitigationMember" xlink:label="loc_us-gaap_SettledLitigationMember_6C15036B5170A5CBE67AB9809BC844A3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LitigationStatusDomain_EE6CA47F1B237D03CEE4B9809BC828F0" xlink:to="loc_us-gaap_SettledLitigationMember_6C15036B5170A5CBE67AB9809BC844A3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_D616C4342CCD1946E211B9809BC83545" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LossContingenciesTable_A856818B62E7B0F649D7B9809BC8B79C" xlink:to="loc_us-gaap_LossContingenciesLineItems_D616C4342CCD1946E211B9809BC83545" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromLegalSettlements" xlink:label="loc_us-gaap_ProceedsFromLegalSettlements_4D29BDA07C2D5F08D014B9809BC80B1F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LossContingenciesLineItems_D616C4342CCD1946E211B9809BC83545" xlink:to="loc_us-gaap_ProceedsFromLegalSettlements_4D29BDA07C2D5F08D014B9809BC80B1F" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_LossContingencyAmortizationPeriodofCovenantNottoSue" xlink:label="loc_ftnt_LossContingencyAmortizationPeriodofCovenantNottoSue_EC2E944D0FD1D90E17F8B9809BC83774" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LossContingenciesLineItems_D616C4342CCD1946E211B9809BC83545" xlink:to="loc_ftnt_LossContingencyAmortizationPeriodofCovenantNottoSue_EC2E944D0FD1D90E17F8B9809BC83774" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ProceedsfromLegalSettlementUsedtoOffsetContingentLegalFees" xlink:label="loc_ftnt_ProceedsfromLegalSettlementUsedtoOffsetContingentLegalFees_8F2F95CF661418B8EBB7B9809BC8F932" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LossContingenciesLineItems_D616C4342CCD1946E211B9809BC83545" xlink:to="loc_ftnt_ProceedsfromLegalSettlementUsedtoOffsetContingentLegalFees_8F2F95CF661418B8EBB7B9809BC8F932" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ProceedsfromLegalSettlementDeferred" xlink:label="loc_ftnt_ProceedsfromLegalSettlementDeferred_5DB4BF4ACC7687343E19B9809BC968DD" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LossContingenciesLineItems_D616C4342CCD1946E211B9809BC83545" xlink:to="loc_ftnt_ProceedsfromLegalSettlementDeferred_5DB4BF4ACC7687343E19B9809BC968DD" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/CommitmentsAndContingenciesMinimumOperatingLeasePaymentsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_51D39CA230EFD8B37019B9809BD060ED" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_51D39CA230EFD8B37019B9809BD060ED" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_B31700F6AFBD0DCA8065B9809BD00D07" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_B31700F6AFBD0DCA8065B9809BD00D07" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_3B79DE76D13D80393723B9809BD07971" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_3B79DE76D13D80393723B9809BD07971" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_280C0D747E9C75F29AE2B9809BD0BF90" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_280C0D747E9C75F29AE2B9809BD0BF90" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_194202F60D9E58DAAD7DB9809BD006CA" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears_194202F60D9E58DAAD7DB9809BD006CA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_78284DE64D5002AF003DB9809BD0233D" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears_78284DE64D5002AF003DB9809BD0233D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_D4D15C07F372A990D242B9809BD0AA4C" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_D4D15C07F372A990D242B9809BD0AA4C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_7F95E6E552FAB94D8C5BB9809BD10B43" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_8852B22345D23D4F337BB9809BD04CDA" xlink:to="loc_us-gaap_OperatingLeasesFutureMinimumPaymentsDue_7F95E6E552FAB94D8C5BB9809BD10B43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligationFiscalYearMaturityAbstract" xlink:label="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_51D39CA230EFD8B37019B9809BD060ED" xlink:to="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligationDueInNextTwelveMonths" xlink:label="loc_us-gaap_PurchaseObligationDueInNextTwelveMonths_A36D5C8B7FF48E38FD96B9809BD1311D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:to="loc_us-gaap_PurchaseObligationDueInNextTwelveMonths_A36D5C8B7FF48E38FD96B9809BD1311D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligationDueInSecondYear" xlink:label="loc_us-gaap_PurchaseObligationDueInSecondYear_FBB70247B9589E9D1F77B9809BD129B4" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:to="loc_us-gaap_PurchaseObligationDueInSecondYear_FBB70247B9589E9D1F77B9809BD129B4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligationDueInThirdYear" xlink:label="loc_us-gaap_PurchaseObligationDueInThirdYear_7593D6099C50584B88CAB9809BD1E39A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:to="loc_us-gaap_PurchaseObligationDueInThirdYear_7593D6099C50584B88CAB9809BD1E39A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligationDueInFourthYear" xlink:label="loc_us-gaap_PurchaseObligationDueInFourthYear_570EA635293D28F20126B9809BD16965" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:to="loc_us-gaap_PurchaseObligationDueInFourthYear_570EA635293D28F20126B9809BD16965" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligationDueInFifthYear" xlink:label="loc_us-gaap_PurchaseObligationDueInFifthYear_725B5D8C4C233DE8A535B9809BD11D74" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:to="loc_us-gaap_PurchaseObligationDueInFifthYear_725B5D8C4C233DE8A535B9809BD11D74" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligationDueAfterFifthYear" xlink:label="loc_us-gaap_PurchaseObligationDueAfterFifthYear_B188BF94FA3BB2B5A345B9809BD13CD3" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:to="loc_us-gaap_PurchaseObligationDueAfterFifthYear_B188BF94FA3BB2B5A345B9809BD13CD3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PurchaseObligation" xlink:label="loc_us-gaap_PurchaseObligation_D70D3D90BA5326ECADB5B9809BD11E11" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PurchaseObligationFiscalYearMaturityAbstract_8EBA96B7D256882CEEBEB9809BD1D749" xlink:to="loc_us-gaap_PurchaseObligation_D70D3D90BA5326ECADB5B9809BD11E11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherCommitmentsAbstract" xlink:label="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_51D39CA230EFD8B37019B9809BD060ED" xlink:to="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractualObligationDueInNextTwelveMonths" xlink:label="loc_us-gaap_ContractualObligationDueInNextTwelveMonths_9AD231C3C5B86E30AE27B9809BD17643" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:to="loc_us-gaap_ContractualObligationDueInNextTwelveMonths_9AD231C3C5B86E30AE27B9809BD17643" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractualObligationDueInSecondYear" xlink:label="loc_us-gaap_ContractualObligationDueInSecondYear_7A9B2BE9164A530D8F86B9809BD169E0" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:to="loc_us-gaap_ContractualObligationDueInSecondYear_7A9B2BE9164A530D8F86B9809BD169E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractualObligationDueInThirdYear" xlink:label="loc_us-gaap_ContractualObligationDueInThirdYear_AFBEEADED9D346397823B9809BD11DAF" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:to="loc_us-gaap_ContractualObligationDueInThirdYear_AFBEEADED9D346397823B9809BD11DAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractualObligationDueInFourthYear" xlink:label="loc_us-gaap_ContractualObligationDueInFourthYear_52B2F849E1CFF6B0C389B9809BD2A7BB" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:to="loc_us-gaap_ContractualObligationDueInFourthYear_52B2F849E1CFF6B0C389B9809BD2A7BB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractualObligationDueInFifthYear" xlink:label="loc_us-gaap_ContractualObligationDueInFifthYear_B0397399E5548C934584B9809BD2B2C9" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:to="loc_us-gaap_ContractualObligationDueInFifthYear_B0397399E5548C934584B9809BD2B2C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractualObligationDueAfterFifthYear" xlink:label="loc_us-gaap_ContractualObligationDueAfterFifthYear_86E79CDB01DD046AC918B9809BD2C7FB" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:to="loc_us-gaap_ContractualObligationDueAfterFifthYear_86E79CDB01DD046AC918B9809BD2C7FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractualObligation" xlink:label="loc_us-gaap_ContractualObligation_C4C08348B079942BBB66B9809BD109E7" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsAbstract_C3DA2AAE7B513D5A6D1CB9809BD17AE5" xlink:to="loc_us-gaap_ContractualObligation_C4C08348B079942BBB66B9809BD109E7" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/CommitmentsAndContingenciesTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureAbstract" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_07EE1D89BE2FC4730E1ABBEB9BC8C437" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractualObligationFiscalYearMaturityScheduleTableTextBlock" xlink:label="loc_us-gaap_ContractualObligationFiscalYearMaturityScheduleTableTextBlock_86760D115C8DA6837455BBEB9BC8B270" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CommitmentsAndContingenciesDisclosureAbstract_07EE1D89BE2FC4730E1ABBEB9BC8C437" xlink:to="loc_us-gaap_ContractualObligationFiscalYearMaturityScheduleTableTextBlock_86760D115C8DA6837455BBEB9BC8B270" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract_178B6416A6D4692FFC04B5D76455CC07" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_378137EA1229AAF9EBD5B5D7645683EA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_178B6416A6D4692FFC04B5D76455CC07" xlink:to="loc_us-gaap_StatementTable_378137EA1229AAF9EBD5B5D7645683EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_A0D5B961FE50C8119328B5D764561B80" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_378137EA1229AAF9EBD5B5D7645683EA" xlink:to="loc_us-gaap_StatementScenarioAxis_A0D5B961FE50C8119328B5D764561B80" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_549E29466BAAA9EEBC5FB5D76456C487" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementScenarioAxis_A0D5B961FE50C8119328B5D764561B80" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_549E29466BAAA9EEBC5FB5D76456C487" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_48008D06CFD9B42B2CBCB5D764562A8C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_378137EA1229AAF9EBD5B5D7645683EA" xlink:to="loc_us-gaap_StatementLineItems_48008D06CFD9B42B2CBCB5D764562A8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_48008D06CFD9B42B2CBCB5D764562A8C" xlink:to="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_61964EA20ECAD92A95BBB5D76456E3DD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:to="loc_us-gaap_AssetsCurrentAbstract_61964EA20ECAD92A95BBB5D76456E3DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_E0914BAF1AAF5AB5F9A7B5D76456586A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_61964EA20ECAD92A95BBB5D76456E3DD" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_E0914BAF1AAF5AB5F9A7B5D76456586A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShortTermInvestments" xlink:label="loc_us-gaap_ShortTermInvestments_DBE02824E76C7309548CB5D76457A076" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_61964EA20ECAD92A95BBB5D76456E3DD" xlink:to="loc_us-gaap_ShortTermInvestments_DBE02824E76C7309548CB5D76457A076" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_7F99BAD605B9E1F69D68B5D76457C9BD" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_61964EA20ECAD92A95BBB5D76456E3DD" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_7F99BAD605B9E1F69D68B5D76457C9BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_ACB15C25177B934C5D29B5D76457267E" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_61964EA20ECAD92A95BBB5D76456E3DD" xlink:to="loc_us-gaap_InventoryNet_ACB15C25177B934C5D29B5D76457267E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_1343A2B37AE91F2B99EEB5D76457961B" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_61964EA20ECAD92A95BBB5D76456E3DD" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_1343A2B37AE91F2B99EEB5D76457961B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_4F8AA7968D9468DA0761B5D76457DDC7" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_61964EA20ECAD92A95BBB5D76456E3DD" xlink:to="loc_us-gaap_AssetsCurrent_4F8AA7968D9468DA0761B5D76457DDC7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermInvestments" xlink:label="loc_us-gaap_LongTermInvestments_A971E725517C3B87B4E2B5D764576310" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:to="loc_us-gaap_LongTermInvestments_A971E725517C3B87B4E2B5D764576310" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_607F8FF6EC1AA6FEA124B5D76457AC52" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_607F8FF6EC1AA6FEA124B5D76457AC52" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:label="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_A373597D63AE73C6C2C8B5D76457C3FD" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:to="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_A373597D63AE73C6C2C8B5D76457C3FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_7AE2A37DCE23E78F7B28B5D7645794A4" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_7AE2A37DCE23E78F7B28B5D7645794A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_6000254493438208C9BDB5D764572989" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:to="loc_us-gaap_Goodwill_6000254493438208C9BDB5D764572989" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_486951C2C01C56172392B5D76457B43F" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_486951C2C01C56172392B5D76457B43F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_7714F3FA4B56A8FD8195B5D764582DE4" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_4D48FE7D6E017D2832D5B5D76456AF7C" xlink:to="loc_us-gaap_Assets_7714F3FA4B56A8FD8195B5D764582DE4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_48008D06CFD9B42B2CBCB5D764562A8C" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_B8233BD58C0873670463B5D764584932" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_B8233BD58C0873670463B5D764584932" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_C53D78E67798286E8202B5D764580162" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_B8233BD58C0873670463B5D764584932" xlink:to="loc_us-gaap_AccountsPayableCurrent_C53D78E67798286E8202B5D764580162" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_0709C0E15D2B55B5BEE5B5D7645863F1" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_B8233BD58C0873670463B5D764584932" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_0709C0E15D2B55B5BEE5B5D7645863F1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_A7E035D78DA7E9EA9E4BB5D764583468" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_B8233BD58C0873670463B5D764584932" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_A7E035D78DA7E9EA9E4BB5D764583468" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccruedIncomeTaxesCurrent" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_AE1FA20AF081FC359B65B5D76458DA49" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_B8233BD58C0873670463B5D764584932" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_AE1FA20AF081FC359B65B5D76458DA49" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="loc_us-gaap_DeferredRevenueCurrent_C51FE012C4B50D8AEE8DB5D764590538" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_B8233BD58C0873670463B5D764584932" xlink:to="loc_us-gaap_DeferredRevenueCurrent_C51FE012C4B50D8AEE8DB5D764590538" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_369A27FAC9D5FC021B03B5D7645908F4" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_B8233BD58C0873670463B5D764584932" xlink:to="loc_us-gaap_LiabilitiesCurrent_369A27FAC9D5FC021B03B5D7645908F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredRevenueNoncurrent" xlink:label="loc_us-gaap_DeferredRevenueNoncurrent_A9D047ADCA8D511AB370B5D764595C08" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:to="loc_us-gaap_DeferredRevenueNoncurrent_A9D047ADCA8D511AB370B5D764595C08" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccruedIncomeTaxesNoncurrent" xlink:label="loc_us-gaap_AccruedIncomeTaxesNoncurrent_EFF61D78B1EB61042105B5D76459E888" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:to="loc_us-gaap_AccruedIncomeTaxesNoncurrent_EFF61D78B1EB61042105B5D76459E888" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_CD9408A2F51396287052B5D764598A13" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_CD9408A2F51396287052B5D764598A13" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_7D0DAF86CB6ED25A013FB5D7645966D4" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:to="loc_us-gaap_Liabilities_7D0DAF86CB6ED25A013FB5D7645966D4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="loc_us-gaap_CommitmentsAndContingencies_9B6B9B58722EF328553DB5D764590604" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:to="loc_us-gaap_CommitmentsAndContingencies_9B6B9B58722EF328553DB5D764590604" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaap_StockholdersEquityAbstract_89DBFD33F78FB394B659B5D76459E2E6" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:to="loc_us-gaap_StockholdersEquityAbstract_89DBFD33F78FB394B659B5D76459E2E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_7E53CCCC1A6DB2287AE9B5D76459466F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_89DBFD33F78FB394B659B5D76459E2E6" xlink:to="loc_us-gaap_CommonStockValue_7E53CCCC1A6DB2287AE9B5D76459466F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_6ECAFFB6B9CD90EE4AEBB5D7645AB148" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_89DBFD33F78FB394B659B5D76459E2E6" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_6ECAFFB6B9CD90EE4AEBB5D7645AB148" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_5E58EADC183AC1A1FCA7B5D7645AE7A4" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_89DBFD33F78FB394B659B5D76459E2E6" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_5E58EADC183AC1A1FCA7B5D7645AE7A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_CDD3A3BC2AEA83F18AEDB5D7645A4DDD" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_89DBFD33F78FB394B659B5D76459E2E6" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_CDD3A3BC2AEA83F18AEDB5D7645A4DDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_55D7B29A1A8731AED103B5D7645A873A" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_89DBFD33F78FB394B659B5D76459E2E6" xlink:to="loc_us-gaap_StockholdersEquity_55D7B29A1A8731AED103B5D7645A873A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_AC5E034766351180B4D9B5D7645AD745" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_87D5F4D91031D277F279B5D76458FD29" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_AC5E034766351180B4D9B5D7645AD745" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/ConsolidatedBalanceSheetsParenthetical" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract_B01E57584757B50C17D1BBEB9C6C386F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_EA7F6700A7B7D66C8E52BBEB9C6C5AEB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_B01E57584757B50C17D1BBEB9C6C386F" xlink:to="loc_us-gaap_StatementTable_EA7F6700A7B7D66C8E52BBEB9C6C5AEB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_ABB54EBC8D38156620F3BBEB9C6C63EC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_EA7F6700A7B7D66C8E52BBEB9C6C5AEB" xlink:to="loc_us-gaap_StatementScenarioAxis_ABB54EBC8D38156620F3BBEB9C6C63EC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_E81B0DE26F273CAFB6B9BBEB9C6C86F0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementScenarioAxis_ABB54EBC8D38156620F3BBEB9C6C63EC" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_E81B0DE26F273CAFB6B9BBEB9C6C86F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_74C7E4817032082317AEBBEB9C6C5F16" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_EA7F6700A7B7D66C8E52BBEB9C6C5AEB" xlink:to="loc_us-gaap_StatementLineItems_74C7E4817032082317AEBBEB9C6C5F16" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AllowanceForDoubtfulAccountsReceivableandSalesReturns" xlink:label="loc_ftnt_AllowanceForDoubtfulAccountsReceivableandSalesReturns_60722F995C7F4881E3ECBBEB9C6C7E56" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_74C7E4817032082317AEBBEB9C6C5F16" xlink:to="loc_ftnt_AllowanceForDoubtfulAccountsReceivableandSalesReturns_60722F995C7F4881E3ECBBEB9C6C7E56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_93641CC50D7DF91C5886BBEB9C6C46CE" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_74C7E4817032082317AEBBEB9C6C5F16" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_93641CC50D7DF91C5886BBEB9C6C46CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_2339B28D3D5560954182BBEB9C6CF757" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_74C7E4817032082317AEBBEB9C6C5F16" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_2339B28D3D5560954182BBEB9C6CF757" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_0199DB6145D6B3AC8896BBEB9C6CD93B" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_74C7E4817032082317AEBBEB9C6C5F16" xlink:to="loc_us-gaap_CommonStockSharesIssued_0199DB6145D6B3AC8896BBEB9C6CD93B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_0AB5C1C4B2D589DED17DBBEB9C6C5927" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_74C7E4817032082317AEBBEB9C6C5F16" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_0AB5C1C4B2D589DED17DBBEB9C6C5927" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="loc_us-gaap_StatementOfCashFlowsAbstract_587FC0E3F5E34924E160B5D764204118" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_64C740EB47930DFBFDB0B5D7642023C6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract_587FC0E3F5E34924E160B5D764204118" xlink:to="loc_us-gaap_StatementTable_64C740EB47930DFBFDB0B5D7642023C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_BF70F3A5D35EBC9B0A36B5D764204489" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_64C740EB47930DFBFDB0B5D7642023C6" xlink:to="loc_us-gaap_StatementScenarioAxis_BF70F3A5D35EBC9B0A36B5D764204489" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_A5824C522890994F4F28B5D76420138A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementScenarioAxis_BF70F3A5D35EBC9B0A36B5D764204489" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_A5824C522890994F4F28B5D76420138A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_64C740EB47930DFBFDB0B5D7642023C6" xlink:to="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_B01D53BD31C13F96B75DB5D76420B85A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_B01D53BD31C13F96B75DB5D76420B85A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_485AF482292732E5D45FB5D76420BBE5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_B01D53BD31C13F96B75DB5D76420B85A" xlink:to="loc_us-gaap_NetIncomeLoss_485AF482292732E5D45FB5D76420BBE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_13BE3DF38A1D48D4B894B5D764214558" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_B01D53BD31C13F96B75DB5D76420B85A" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_13BE3DF38A1D48D4B894B5D764214558" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_3B4E234C3BDA1790D799B5D76421FC51" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_13BE3DF38A1D48D4B894B5D764214558" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_3B4E234C3BDA1790D799B5D76421FC51" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_73BA986B58A8A37A7F08B5D76421CB25" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_13BE3DF38A1D48D4B894B5D764214558" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_73BA986B58A8A37A7F08B5D76421CB25" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_4627C4BEACD724166110B5D7642187A2" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_13BE3DF38A1D48D4B894B5D764214558" xlink:to="loc_us-gaap_ShareBasedCompensation_4627C4BEACD724166110B5D7642187A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherNoncashIncomeExpense" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_1D7CB38067EB54A3D688B5D76421DF2D" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_13BE3DF38A1D48D4B894B5D764214558" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_1D7CB38067EB54A3D688B5D76421DF2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_B01D53BD31C13F96B75DB5D76420B85A" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_6729E4A0968CABB335B3B5D764212EA1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_6729E4A0968CABB335B3B5D764212EA1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_5A20C80C119672225E3DB5D76421C697" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_5A20C80C119672225E3DB5D76421C697" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_DCD8589D3C186C29321CB5D76421B575" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_DCD8589D3C186C29321CB5D76421B575" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredIncomeTaxes" xlink:label="loc_us-gaap_IncreaseDecreaseInDeferredIncomeTaxes_58C015F73D0CB6E13967B5D764216659" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInDeferredIncomeTaxes_58C015F73D0CB6E13967B5D764216659" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_FB111BD6568DFB860C42B5D76421EABA" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_FB111BD6568DFB860C42B5D76421EABA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_557F7E31D01C1B6383D0B5D764213AD0" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_557F7E31D01C1B6383D0B5D764213AD0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_F94368AAB1231F4CBE67B5D76422B9D2" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_F94368AAB1231F4CBE67B5D76422B9D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_4246C069150174126729B5D764229BEF" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInEmployeeRelatedLiabilities_4246C069150174126729B5D764229BEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_AE0D0136CEBF2FA791E8B5D76422E1F8" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_AE0D0136CEBF2FA791E8B5D76422E1F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_769D000594038E5DBB2BB5D76422E6D7" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_769D000594038E5DBB2BB5D76422E6D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_C160E60DADA128C49974B5D764221AC5" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssetsAndLiabilitiesNetAbstract_0CBC83C232CD02E515BFB5D764214174" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_C160E60DADA128C49974B5D764221AC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_4AC876E8CE1674FCA10FB5D76422B7EE" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_B01D53BD31C13F96B75DB5D76420B85A" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_4AC876E8CE1674FCA10FB5D76422B7EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_EE854740DE8C9BD18370B5D7642285F0" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_EE854740DE8C9BD18370B5D7642285F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireInvestments" xlink:label="loc_us-gaap_PaymentsToAcquireInvestments_169EDC75FA7EB72DE0C7B5D76422E5C2" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_EE854740DE8C9BD18370B5D7642285F0" xlink:to="loc_us-gaap_PaymentsToAcquireInvestments_169EDC75FA7EB72DE0C7B5D76422E5C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities_578DF5D364B47EA45A24B5D76422643B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_EE854740DE8C9BD18370B5D7642285F0" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities_578DF5D364B47EA45A24B5D76422643B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_E58696B7F2C92E03C18CB5D76422E24A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_EE854740DE8C9BD18370B5D7642285F0" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_E58696B7F2C92E03C18CB5D76422E24A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireProductiveAssets" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_A36ACA992C504D6D597DB5D76422244A" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_EE854740DE8C9BD18370B5D7642285F0" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_A36ACA992C504D6D597DB5D76422244A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_E77055C0ABA9699D9146B5D764223BB6" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_EE854740DE8C9BD18370B5D7642285F0" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_E77055C0ABA9699D9146B5D764223BB6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_DF5BB6AC819E16C50406B5D764225C38" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_EE854740DE8C9BD18370B5D7642285F0" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_DF5BB6AC819E16C50406B5D764225C38" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_232D2DEBA5B9B80B33A5B5D7642209D3" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_232D2DEBA5B9B80B33A5B5D7642209D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_CCBFBF5E1EBF94A048F2B5D764233172" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_232D2DEBA5B9B80B33A5B5D7642209D3" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_CCBFBF5E1EBF94A048F2B5D764233172" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_0F16C4B442360E79FB37B5D76422D1E6" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_232D2DEBA5B9B80B33A5B5D7642209D3" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_0F16C4B442360E79FB37B5D76422D1E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_DF96716F09EDC29DFCF5B5D7642331E9" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_232D2DEBA5B9B80B33A5B5D7642209D3" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_DF96716F09EDC29DFCF5B5D7642331E9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RepaymentsOfAssumedDebt" xlink:label="loc_us-gaap_RepaymentsOfAssumedDebt_9D84EC0866D9F2D13D61B5D764233FE1" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_232D2DEBA5B9B80B33A5B5D7642209D3" xlink:to="loc_us-gaap_RepaymentsOfAssumedDebt_9D84EC0866D9F2D13D61B5D764233FE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_032870C9B725C765D360B5D76423709F" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_232D2DEBA5B9B80B33A5B5D7642209D3" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_032870C9B725C765D360B5D76423709F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_2AD1F189182388DFB9C0B5D7642339D5" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:to="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_2AD1F189182388DFB9C0B5D7642339D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_AE565DE720551AF6208AB5D76423BFB1" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_AE565DE720551AF6208AB5D76423BFB1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_18E6E9B393584845F809B5D764232E44" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_18E6E9B393584845F809B5D764232E44" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_7874E1120BA5C3BF38D6B5D764236898" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_7874E1120BA5C3BF38D6B5D764236898" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxesPaidNet" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_66412128A22DCEE3FC2DB5D76423EAA2" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_7874E1120BA5C3BF38D6B5D764236898" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_66412128A22DCEE3FC2DB5D76423EAA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:label="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_A37C59BA087063DE546DB5D76423490C" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_D3807128263CB19DAE33B5D76420703D" xlink:to="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_A37C59BA087063DE546DB5D76423490C" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_TransfersofEvaluationUnitsfromInventorytoPropertyandEquipment" xlink:label="loc_ftnt_TransfersofEvaluationUnitsfromInventorytoPropertyandEquipment_1653900A52C1F5CF00EEB5D76423BBAC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_A37C59BA087063DE546DB5D76423490C" xlink:to="loc_ftnt_TransfersofEvaluationUnitsfromInventorytoPropertyandEquipment_1653900A52C1F5CF00EEB5D76423BBAC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:label="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid_45C9518BAB405128260CB5D764243EFD" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_A37C59BA087063DE546DB5D76423490C" xlink:to="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid_45C9518BAB405128260CB5D764243EFD" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_BusinessAcquisitionEquityAwardsAssumed" xlink:label="loc_ftnt_BusinessAcquisitionEquityAwardsAssumed_1198D34E6DBCD7793670B5D76424AD74" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_A37C59BA087063DE546DB5D76423490C" xlink:to="loc_ftnt_BusinessAcquisitionEquityAwardsAssumed_1198D34E6DBCD7793670B5D76424AD74" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/ConsolidatedStatementsOfComprehensiveIncome" xlink:type="extended">
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ConsolidatedStatementsOfComprehensiveIncomeAbstract" xlink:label="loc_ftnt_ConsolidatedStatementsOfComprehensiveIncomeAbstract_5E1220088DA8085E7F2AB5D7642EEBBB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_8B0F7327563E21CB1E84B5D7642E215F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ConsolidatedStatementsOfComprehensiveIncomeAbstract_5E1220088DA8085E7F2AB5D7642EEBBB" xlink:to="loc_us-gaap_StatementTable_8B0F7327563E21CB1E84B5D7642E215F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_39EDC8D67CBD33E74405B5D7642EDBE4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_8B0F7327563E21CB1E84B5D7642E215F" xlink:to="loc_us-gaap_StatementScenarioAxis_39EDC8D67CBD33E74405B5D7642EDBE4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_85591DA56222BAAD659FB5D7642EF07E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementScenarioAxis_39EDC8D67CBD33E74405B5D7642EDBE4" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_85591DA56222BAAD659FB5D7642EF07E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_1DB4458B0C3321F56A79B5D7642E4A01" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_8B0F7327563E21CB1E84B5D7642E215F" xlink:to="loc_us-gaap_StatementLineItems_1DB4458B0C3321F56A79B5D7642E4A01" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_CB5715823AD85CC863A6B5D7642E9E76" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_1DB4458B0C3321F56A79B5D7642E4A01" xlink:to="loc_us-gaap_NetIncomeLoss_CB5715823AD85CC863A6B5D7642E9E76" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParentAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParentAbstract_839ECF530FED35DFD0F4B5D7642F36DC" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_1DB4458B0C3321F56A79B5D7642E4A01" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParentAbstract_839ECF530FED35DFD0F4B5D7642F36DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_6D2C62E7975FAA2223F5B5D7642FE122" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParentAbstract_839ECF530FED35DFD0F4B5D7642F36DC" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_6D2C62E7975FAA2223F5B5D7642FE122" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1_5DC7C9E6383E4347C3E0B5D7642F00DF" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParentAbstract_839ECF530FED35DFD0F4B5D7642F36DC" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1_5DC7C9E6383E4347C3E0B5D7642F00DF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_506D2E9AE079CFF7F03CB5D7642F4F8A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParentAbstract_839ECF530FED35DFD0F4B5D7642F36DC" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_506D2E9AE079CFF7F03CB5D7642F4F8A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_ED79F01A27DF131817F7B5D7642F780B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_1DB4458B0C3321F56A79B5D7642E4A01" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_ED79F01A27DF131817F7B5D7642F780B" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/ConsolidatedStatementsOfOperations" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="loc_us-gaap_IncomeStatementAbstract_327AD0FD846D1667E9A8B5D7643BCE33" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_D8094B8994CC9F1904DEB5D7643BAD8C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_327AD0FD846D1667E9A8B5D7643BCE33" xlink:to="loc_us-gaap_StatementTable_D8094B8994CC9F1904DEB5D7643BAD8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_5C91A2D9A099E4A91E7EB5D7643B1215" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_D8094B8994CC9F1904DEB5D7643BAD8C" xlink:to="loc_us-gaap_StatementScenarioAxis_5C91A2D9A099E4A91E7EB5D7643B1215" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_E4C7B188DC5993FF84B7B5D7643BB620" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementScenarioAxis_5C91A2D9A099E4A91E7EB5D7643B1215" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_E4C7B188DC5993FF84B7B5D7643BB620" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_D8094B8994CC9F1904DEB5D7643BAD8C" xlink:to="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesRevenueNetAbstract" xlink:label="loc_us-gaap_SalesRevenueNetAbstract_2EEDF667F19F5FA7B150B5D7643C10F4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_SalesRevenueNetAbstract_2EEDF667F19F5FA7B150B5D7643C10F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesRevenueGoodsNet" xlink:label="loc_us-gaap_SalesRevenueGoodsNet_A37D3B7AAF7DC9DADED0B5D7643C4071" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SalesRevenueNetAbstract_2EEDF667F19F5FA7B150B5D7643C10F4" xlink:to="loc_us-gaap_SalesRevenueGoodsNet_A37D3B7AAF7DC9DADED0B5D7643C4071" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesRevenueServicesNet" xlink:label="loc_us-gaap_SalesRevenueServicesNet_41D29B261A24150FE82FB5D7643C0765" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SalesRevenueNetAbstract_2EEDF667F19F5FA7B150B5D7643C10F4" xlink:to="loc_us-gaap_SalesRevenueServicesNet_41D29B261A24150FE82FB5D7643C0765" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_DD00C590F175BF9B88D4B5D7643CB475" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SalesRevenueNetAbstract_2EEDF667F19F5FA7B150B5D7643C10F4" xlink:to="loc_us-gaap_SalesRevenueNet_DD00C590F175BF9B88D4B5D7643CB475" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfGoodsAndServicesSoldAbstract" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_07F7EC5C3690AFAC1388B5D7643C8B49" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_07F7EC5C3690AFAC1388B5D7643C8B49" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfGoodsSold" xlink:label="loc_us-gaap_CostOfGoodsSold_BF25C1A92058CA8CDBB0B5D7643C40B7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_07F7EC5C3690AFAC1388B5D7643C8B49" xlink:to="loc_us-gaap_CostOfGoodsSold_BF25C1A92058CA8CDBB0B5D7643C40B7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfServices" xlink:label="loc_us-gaap_CostOfServices_8AFA1F1B891812B79709B5D7643D5D30" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_07F7EC5C3690AFAC1388B5D7643C8B49" xlink:to="loc_us-gaap_CostOfServices_8AFA1F1B891812B79709B5D7643D5D30" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_8C0553F9FCF05D7707DDB5D7643DA128" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CostOfGoodsAndServicesSoldAbstract_07F7EC5C3690AFAC1388B5D7643C8B49" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_8C0553F9FCF05D7707DDB5D7643DA128" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GrossProfitAbstract" xlink:label="loc_us-gaap_GrossProfitAbstract_E1F724725F7C7FAAB623B5D7643DBA65" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_GrossProfitAbstract_E1F724725F7C7FAAB623B5D7643DBA65" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ProductGrossProfit" xlink:label="loc_ftnt_ProductGrossProfit_DEEF89A3439EEBB87943B5D7643D9E97" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GrossProfitAbstract_E1F724725F7C7FAAB623B5D7643DBA65" xlink:to="loc_ftnt_ProductGrossProfit_DEEF89A3439EEBB87943B5D7643D9E97" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ServicesGrossProfit" xlink:label="loc_ftnt_ServicesGrossProfit_E6F7217F0BCB6E8D8E61B5D7643D0D12" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GrossProfitAbstract_E1F724725F7C7FAAB623B5D7643DBA65" xlink:to="loc_ftnt_ServicesGrossProfit_E6F7217F0BCB6E8D8E61B5D7643D0D12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit_D53C2B4A0D2913CF4066B5D7643D57C0" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GrossProfitAbstract_E1F724725F7C7FAAB623B5D7643DBA65" xlink:to="loc_us-gaap_GrossProfit_D53C2B4A0D2913CF4066B5D7643D57C0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="loc_us-gaap_OperatingExpensesAbstract_68208F8E10A409BC233BB5D7643D4EA3" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_OperatingExpensesAbstract_68208F8E10A409BC233BB5D7643D4EA3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_B6904F45D7EF41BBD75DB5D7643D571E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_68208F8E10A409BC233BB5D7643D4EA3" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_B6904F45D7EF41BBD75DB5D7643D571E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SellingAndMarketingExpense" xlink:label="loc_us-gaap_SellingAndMarketingExpense_97AF2A3E539657491CF7B5D7643DCA6D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_68208F8E10A409BC233BB5D7643D4EA3" xlink:to="loc_us-gaap_SellingAndMarketingExpense_97AF2A3E539657491CF7B5D7643DCA6D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_A7B5349637E49A3A908FB5D7643D959A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_68208F8E10A409BC233BB5D7643D4EA3" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_A7B5349637E49A3A908FB5D7643D959A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_572CF88568AD0ACEE1B5B5D7643E8230" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_68208F8E10A409BC233BB5D7643D4EA3" xlink:to="loc_us-gaap_RestructuringCharges_572CF88568AD0ACEE1B5B5D7643E8230" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaap_OperatingExpenses_1EBCC77F39C4813D566AB5D7643E11F7" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_68208F8E10A409BC233BB5D7643D4EA3" xlink:to="loc_us-gaap_OperatingExpenses_1EBCC77F39C4813D566AB5D7643E11F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_2B8F0B1410856DFE30E3B5D7643EFB06" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_OperatingIncomeLoss_2B8F0B1410856DFE30E3B5D7643EFB06" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InvestmentIncomeNet" xlink:label="loc_us-gaap_InvestmentIncomeNet_50298A679D887BD0061FB5D7643EBE42" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_InvestmentIncomeNet_50298A679D887BD0061FB5D7643EBE42" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_7B5E6975D7B5E8C893D5B5D7643EEF87" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_7B5E6975D7B5E8C893D5B5D7643EEF87" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_B4A59BD71E226490447EB5D7643EFF37" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_B4A59BD71E226490447EB5D7643EFF37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_D49F1A387EDD05F53862B5D7643E1735" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_D49F1A387EDD05F53862B5D7643E1735" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_C30CD981F7D1E5BB438FB5D7643E948C" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_NetIncomeLoss_C30CD981F7D1E5BB438FB5D7643E948C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_012659DA1FE778644675B5D7643EB543" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_EarningsPerShareAbstract_012659DA1FE778644675B5D7643EB543" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_E231EE1166F5C35C8DF0B5D7643F7DF1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_012659DA1FE778644675B5D7643EB543" xlink:to="loc_us-gaap_EarningsPerShareBasic_E231EE1166F5C35C8DF0B5D7643F7DF1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_B4D29EA12A6200B32560B5D7643FAEEB" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_012659DA1FE778644675B5D7643EB543" xlink:to="loc_us-gaap_EarningsPerShareDiluted_B4D29EA12A6200B32560B5D7643FAEEB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_58FB8A7D67D576EBDE84B5D7643F6C87" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_3213EC0C023C0F333D2AB5D7643CEA93" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_58FB8A7D67D576EBDE84B5D7643F6C87" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_7A68AAEF0A521E59B282B5D7643FA9AE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_58FB8A7D67D576EBDE84B5D7643F6C87" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_7A68AAEF0A521E59B282B5D7643FA9AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_C9B568EB9927F8BC0198B5D7643F9D4D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_58FB8A7D67D576EBDE84B5D7643F6C87" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_C9B568EB9927F8BC0198B5D7643F9D4D" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/ConsolidatedStatementsOfStockholdersEquity" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="loc_us-gaap_StatementOfStockholdersEquityAbstract_D91AA6C5FD8644557444B9809DF5FB20" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_68D9F0117EF10D18EFA3B9809DF510D7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfStockholdersEquityAbstract_D91AA6C5FD8644557444B9809DF5FB20" xlink:to="loc_us-gaap_StatementTable_68D9F0117EF10D18EFA3B9809DF510D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_DF7F9AAE926E38AA5930B9809DF53224" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_68D9F0117EF10D18EFA3B9809DF510D7" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_DF7F9AAE926E38AA5930B9809DF53224" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_8142044CBD9CC86F6334B9809DF5C8E6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_DF7F9AAE926E38AA5930B9809DF53224" xlink:to="loc_us-gaap_EquityComponentDomain_8142044CBD9CC86F6334B9809DF5C8E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_7C5FFF2C1F30B0993BCEB9809DF53C20" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityComponentDomain_8142044CBD9CC86F6334B9809DF5C8E6" xlink:to="loc_us-gaap_CommonStockMember_7C5FFF2C1F30B0993BCEB9809DF53C20" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_FF44DAB7362ED7DFFDD1B9809DF5FFBA" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityComponentDomain_8142044CBD9CC86F6334B9809DF5C8E6" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_FF44DAB7362ED7DFFDD1B9809DF5FFBA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_D9419072D42AF6E2CC29B9809DF54BC4" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityComponentDomain_8142044CBD9CC86F6334B9809DF5C8E6" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_D9419072D42AF6E2CC29B9809DF54BC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_81313978646448EBFE81B9809DF51247" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityComponentDomain_8142044CBD9CC86F6334B9809DF5C8E6" xlink:to="loc_us-gaap_RetainedEarningsMember_81313978646448EBFE81B9809DF51247" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_B96D94497DB4FF1E7A58B9809DF6B20B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementTable_68D9F0117EF10D18EFA3B9809DF510D7" xlink:to="loc_us-gaap_StatementLineItems_B96D94497DB4FF1E7A58B9809DF6B20B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementLineItems_B96D94497DB4FF1E7A58B9809DF6B20B" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaap_SharesIssued_25CC5C5AA850F5619B27B9809DFA1B61" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_SharesIssued_25CC5C5AA850F5619B27B9809DFA1B61" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_BF0D788F84002B74EBB8B9809DFAE307" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_StockholdersEquity_BF0D788F84002B74EBB8B9809DFAE307" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_StockIssuedDuringPeriodSharesEquityIncentivePlans" xlink:label="loc_ftnt_StockIssuedDuringPeriodSharesEquityIncentivePlans_9BD11FC7725E624696B3B9809DFA8D8F" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_ftnt_StockIssuedDuringPeriodSharesEquityIncentivePlans_9BD11FC7725E624696B3B9809DFA8D8F" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_StockIssuedDuringPeriodValueEquityIncentivePlansNetofTaxesWithheld" xlink:label="loc_ftnt_StockIssuedDuringPeriodValueEquityIncentivePlansNetofTaxesWithheld_0119C2496B4C2BAE3D8CB9809DFA9F78" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_ftnt_StockIssuedDuringPeriodValueEquityIncentivePlansNetofTaxesWithheld_0119C2496B4C2BAE3D8CB9809DFA9F78" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_87FDE9D009751851572BB9809DFA69A9" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_87FDE9D009751851572BB9809DFA69A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_6922A1BADD2973AF3A1FB9809DFA9422" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_6922A1BADD2973AF3A1FB9809DFA9422" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_805154CFE71AD4BF6C92B9809DFB0B95" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_805154CFE71AD4BF6C92B9809DFB0B95" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_D4F2764771912F079B30B9809DFBE2E2" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_D4F2764771912F079B30B9809DFBE2E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet" xlink:label="loc_us-gaap_AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet_C2F34029E5C8AEC897BAB9809DFBBF2D" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet_C2F34029E5C8AEC897BAB9809DFBBF2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_8B05B40E90B4EFA6F273B9809DFB3FEC" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_8B05B40E90B4EFA6F273B9809DFB3FEC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_C67AD2EE45888E4EA4BBB9809DFBFE98" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_NetIncomeLoss_C67AD2EE45888E4EA4BBB9809DFBFE98" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharesIssued" xlink:label="loc_us-gaap_SharesIssued_A0553767E203DF2B0CB0B9809DFB3A9E" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_SharesIssued_A0553767E203DF2B0CB0B9809DFB3A9E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_1438B5D045F1E380B574B9809DFB27CF" xlink:type="locator" />
    <link:presentationArc order="13" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_FE8F5E228A0FEC38BB8FB9809DF63A96" xlink:to="loc_us-gaap_StockholdersEquity_1438B5D045F1E380B574B9809DFB27CF" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/DefinedContributionPlans" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:label="loc_us-gaap_CompensationAndRetirementDisclosureAbstract_FE7BAE06DA7E51AE791ABBEB9C131964" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CompensationAndEmployeeBenefitPlansTextBlock" xlink:label="loc_us-gaap_CompensationAndEmployeeBenefitPlansTextBlock_31CB30A16D304FCB41AFBBEB9C13A562" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CompensationAndRetirementDisclosureAbstract_FE7BAE06DA7E51AE791ABBEB9C131964" xlink:to="loc_us-gaap_CompensationAndEmployeeBenefitPlansTextBlock_31CB30A16D304FCB41AFBBEB9C13A562" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/DefinedContributionPlansDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CompensationAndRetirementDisclosureAbstract" xlink:label="loc_us-gaap_CompensationAndRetirementDisclosureAbstract_20840CDFEDC222FE3436BBEB9BBB91BE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch" xlink:label="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch_CFF389CA636C69CDC0EEBBEB9BBB76AE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CompensationAndRetirementDisclosureAbstract_20840CDFEDC222FE3436BBEB9BBB91BE" xlink:to="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch_CFF389CA636C69CDC0EEBBEB9BBB76AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:label="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_B425991DAA33B01E930DBBEB9BBB24F4" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CompensationAndRetirementDisclosureAbstract_20840CDFEDC222FE3436BBEB9BBB91BE" xlink:to="loc_us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_B425991DAA33B01E930DBBEB9BBB24F4" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_DefinedContributionPlanEmployerMatchingContributionAmount" xlink:label="loc_ftnt_DefinedContributionPlanEmployerMatchingContributionAmount_543B9BD9DFC0A6F9CB08BBEB9BBB1FCD" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CompensationAndRetirementDisclosureAbstract_20840CDFEDC222FE3436BBEB9BBB91BE" xlink:to="loc_ftnt_DefinedContributionPlanEmployerMatchingContributionAmount_543B9BD9DFC0A6F9CB08BBEB9BBB1FCD" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/DocumentAndEntityInformation" xlink:type="extended">
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_DeiAbstract" xlink:label="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName_4684B80AFC547C8436B3BBEB9C3FDDF3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_EntityRegistrantName_4684B80AFC547C8436B3BBEB9C3FDDF3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey_0ED76914CEA21F6D9F6EBBEB9C40B20E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_EntityCentralIndexKey_0ED76914CEA21F6D9F6EBBEB9C40B20E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType_221B01BC2181E88C3535BBEB9C40B699" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_DocumentType_221B01BC2181E88C3535BBEB9C40B699" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_90668F2EE9ABB313834ABBEB9C407FD8" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_DocumentPeriodEndDate_90668F2EE9ABB313834ABBEB9C407FD8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag_E19A038E15C9F7A4158DBBEB9C40676C" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_AmendmentFlag_E19A038E15C9F7A4158DBBEB9C40676C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus_E68BF2224D9952E2EEC4BBEB9C401524" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_DocumentFiscalYearFocus_E68BF2224D9952E2EEC4BBEB9C401524" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus_59F2AF46D7591B340F9FBBEB9C40760F" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_DocumentFiscalPeriodFocus_59F2AF46D7591B340F9FBBEB9C40760F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate_0B24AE7DAC8739EC9E11BBEB9C40F971" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_CurrentFiscalYearEndDate_0B24AE7DAC8739EC9E11BBEB9C40F971" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCurrentReportingStatus" xlink:label="loc_dei_EntityCurrentReportingStatus_2628C0AB9B54A3AE5A6CBBEB9C40708C" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_EntityCurrentReportingStatus_2628C0AB9B54A3AE5A6CBBEB9C40708C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory_E12F99E4395599457D62BBEB9C4095A7" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_EntityFilerCategory_E12F99E4395599457D62BBEB9C4095A7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer_CF8A0D5CBF7866B505D5BBEB9C407DD5" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_EntityWellKnownSeasonedIssuer_CF8A0D5CBF7866B505D5BBEB9C407DD5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityVoluntaryFilers" xlink:label="loc_dei_EntityVoluntaryFilers_45E53F6FCC341E2D95D7BBEB9C40DDEA" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_EntityVoluntaryFilers_45E53F6FCC341E2D95D7BBEB9C40DDEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_823101865A0CC85BF0DCBBEB9C400C2D" xlink:type="locator" />
    <link:presentationArc order="13" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_823101865A0CC85BF0DCBBEB9C400C2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityPublicFloat" xlink:label="loc_dei_EntityPublicFloat_961558E82DF57D95F1C3BBEB9C40D8A6" xlink:type="locator" />
    <link:presentationArc order="14" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeiAbstract_8385FA36391ACBAB0534BBEB9C3F6910" xlink:to="loc_dei_EntityPublicFloat_961558E82DF57D95F1C3BBEB9C40D8A6" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/FinancialInstrumentsAndFairValue" xlink:type="extended">
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_FinancialInstrumentsAndFairValueAbstract" xlink:label="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_A286C8B961891A8532AFBBEB9BBC5A34" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FinancialInstrumentsDisclosureTextBlock" xlink:label="loc_us-gaap_FinancialInstrumentsDisclosureTextBlock_73E354F74F5A160C4688BBEB9BBCF61A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_A286C8B961891A8532AFBBEB9BBC5A34" xlink:to="loc_us-gaap_FinancialInstrumentsDisclosureTextBlock_73E354F74F5A160C4688BBEB9BBCF61A" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/FinancialInstrumentsAndFairValueAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_FinancialInstrumentsAndFairValueAbstract" xlink:label="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_03BB6F015DAC61A80694B5EFC55E3ECC" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_DE07E1FE994509D10000B5D7635AFD04" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_03BB6F015DAC61A80694B5EFC55E3ECC" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_DE07E1FE994509D10000B5D7635AFD04" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4A5A4E342DF59635F563B5D7635A0063" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_DE07E1FE994509D10000B5D7635AFD04" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4A5A4E342DF59635F563B5D7635A0063" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_781D1120712F3D8FB81BB5D7635AEC48" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_4A5A4E342DF59635F563B5D7635A0063" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_781D1120712F3D8FB81BB5D7635AEC48" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsNonrecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_A42395408DD52D0CB082B5D7635A1B32" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_781D1120712F3D8FB81BB5D7635AEC48" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_A42395408DD52D0CB082B5D7635A1B32" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_4BD56967F28B9D1B2DB6B5D7635B5F46" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_DE07E1FE994509D10000B5D7635AFD04" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_4BD56967F28B9D1B2DB6B5D7635B5F46" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_C338C1E47247B072F290B5D76360D9A6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_4BD56967F28B9D1B2DB6B5D7635B5F46" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_C338C1E47247B072F290B5D76360D9A6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfSalesMember" xlink:label="loc_us-gaap_CostOfSalesMember_BA79BF95475949E97142B5D763609858" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_C338C1E47247B072F290B5D76360D9A6" xlink:to="loc_us-gaap_CostOfSalesMember_BA79BF95475949E97142B5D763609858" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_897597BA01B8214E0241B5D763603AE1" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_DE07E1FE994509D10000B5D7635AFD04" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_897597BA01B8214E0241B5D763603AE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FF8D8DDA6F6DC9ADFE7DB5D7636091BE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_897597BA01B8214E0241B5D763603AE1" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FF8D8DDA6F6DC9ADFE7DB5D7636091BE" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_CoyotePointSystemsInc.Member" xlink:label="loc_ftnt_CoyotePointSystemsInc.Member_2F6D624C8A9DE12367B7B5D76360F8B4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_FF8D8DDA6F6DC9ADFE7DB5D7636091BE" xlink:to="loc_ftnt_CoyotePointSystemsInc.Member_2F6D624C8A9DE12367B7B5D76360F8B4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_DBBD3A9D6543D7D85D27B5D76360761C" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_DE07E1FE994509D10000B5D7635AFD04" xlink:to="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_DBBD3A9D6543D7D85D27B5D76360761C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_8898B390BC439D01685CB5D76360179E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_DBBD3A9D6543D7D85D27B5D76360761C" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_8898B390BC439D01685CB5D76360179E" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/FinancialInstrumentsAndFairValueFairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_FinancialInstrumentsAndFairValueAbstract" xlink:label="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_6218C1954E5B9A8599EFB97F2C7C2FB8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_6218C1954E5B9A8599EFB97F2C7C2FB8" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_44EBAD39DC4FEBAAED6FB97FB6A5EA6C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:to="loc_us-gaap_StatementScenarioAxis_44EBAD39DC4FEBAAED6FB97FB6A5EA6C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_D4BB222FAC993C7AB63FB97FB7EC157B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementScenarioAxis_44EBAD39DC4FEBAAED6FB97FB6A5EA6C" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_D4BB222FAC993C7AB63FB97FB7EC157B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioAdjustmentMember" xlink:label="loc_us-gaap_ScenarioAdjustmentMember_B4A4DB6A27BE9E4F2A2CB97FF938E0B1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_D4BB222FAC993C7AB63FB97FB7EC157B" xlink:to="loc_us-gaap_ScenarioAdjustmentMember_B4A4DB6A27BE9E4F2A2CB97FF938E0B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_8A09EDD17B5BA9A52D91B97F2C7C2DA0" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_8A09EDD17B5BA9A52D91B97F2C7C2DA0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_511C7A8C2F58E6ED66FEB9A3B2CE1D8B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_8A09EDD17B5BA9A52D91B97F2C7C2DA0" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_511C7A8C2F58E6ED66FEB9A3B2CE1D8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_2F0D2521F87F8BDBE4F4B9A44809D011" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_511C7A8C2F58E6ED66FEB9A3B2CE1D8B" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_2F0D2521F87F8BDBE4F4B9A44809D011" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_61AB58AD2900B5BCAC6AB97F2C7C2234" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_511C7A8C2F58E6ED66FEB9A3B2CE1D8B" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_61AB58AD2900B5BCAC6AB97F2C7C2234" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_8D2A4067C9A49CD74B41B97F2C7CA3A2" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_511C7A8C2F58E6ED66FEB9A3B2CE1D8B" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_8D2A4067C9A49CD74B41B97F2C7CA3A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_7DEE038A936854AD60F7B97F2C7C812B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_7DEE038A936854AD60F7B97F2C7C812B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_34C00BE47F4D852C1F4DB97F2C7DE70C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_7DEE038A936854AD60F7B97F2C7C812B" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_34C00BE47F4D852C1F4DB97F2C7DE70C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_82607FE63947E62DF172B97F2C7D7754" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_34C00BE47F4D852C1F4DB97F2C7DE70C" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_82607FE63947E62DF172B97F2C7D7754" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_MoneyMarketFundsExcludingCommercialPaperMember" xlink:label="loc_ftnt_MoneyMarketFundsExcludingCommercialPaperMember_463908D1401163AFDAC1B97F2C7D343B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_34C00BE47F4D852C1F4DB97F2C7DE70C" xlink:to="loc_ftnt_MoneyMarketFundsExcludingCommercialPaperMember_463908D1401163AFDAC1B97F2C7D343B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CertificatesOfDepositMember" xlink:label="loc_us-gaap_CertificatesOfDepositMember_D446CC5A15A7C73D43C6B97F2C7D32FA" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_34C00BE47F4D852C1F4DB97F2C7DE70C" xlink:to="loc_us-gaap_CertificatesOfDepositMember_D446CC5A15A7C73D43C6B97F2C7D32FA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember_FB3F68B82A6C0637E3B3B97F2C7D0282" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_34C00BE47F4D852C1F4DB97F2C7DE70C" xlink:to="loc_us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember_FB3F68B82A6C0637E3B3B97F2C7D0282" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_USTreasuryAndGovernmentMember" xlink:label="loc_us-gaap_USTreasuryAndGovernmentMember_38D4B012D1FBCA877464B97F2C7D6D66" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_34C00BE47F4D852C1F4DB97F2C7DE70C" xlink:to="loc_us-gaap_USTreasuryAndGovernmentMember_38D4B012D1FBCA877464B97F2C7D6D66" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_D1B7B59D78428228B5F8B97F2C7D3456" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_34C00BE47F4D852C1F4DB97F2C7DE70C" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_D1B7B59D78428228B5F8B97F2C7D3456" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_56603DC9BBCCD36A998FB97F2C7D7B2C" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_56603DC9BBCCD36A998FB97F2C7D7B2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_7307D8820C696851C016B97F2C7D7AED" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_56603DC9BBCCD36A998FB97F2C7D7B2C" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_7307D8820C696851C016B97F2C7D7AED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_1193547F72C974918246B97F2C7D5E13" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_7307D8820C696851C016B97F2C7D7AED" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_1193547F72C974918246B97F2C7D5E13" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_C1804FEA8E7184EC96C6B97F2C7D99F2" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_C1804FEA8E7184EC96C6B97F2C7D99F2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_4F1DABDF169C7AE3BA64B97F2C7D84FA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_C1804FEA8E7184EC96C6B97F2C7D99F2" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_4F1DABDF169C7AE3BA64B97F2C7D84FA" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_CashEquivalentsLineItemMember" xlink:label="loc_ftnt_CashEquivalentsLineItemMember_11119EB64D5F1F57D442B97F2C7D0848" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_4F1DABDF169C7AE3BA64B97F2C7D84FA" xlink:to="loc_ftnt_CashEquivalentsLineItemMember_11119EB64D5F1F57D442B97F2C7D0848" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShortTermInvestmentsLineItemMember" xlink:label="loc_ftnt_ShortTermInvestmentsLineItemMember_C2481FE6D26E31D3CD03B97F2C7DB467" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_4F1DABDF169C7AE3BA64B97F2C7D84FA" xlink:to="loc_ftnt_ShortTermInvestmentsLineItemMember_C2481FE6D26E31D3CD03B97F2C7DB467" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_LongTermInvestmentsLineItemMember" xlink:label="loc_ftnt_LongTermInvestmentsLineItemMember_4DB6C5D0F36E7A3DD8AAB97F2C7D77B2" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_4F1DABDF169C7AE3BA64B97F2C7D84FA" xlink:to="loc_ftnt_LongTermInvestmentsLineItemMember_4DB6C5D0F36E7A3DD8AAB97F2C7D77B2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0C58DD11A538D08F3F81B97F2C7D6447" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0C58DD11A538D08F3F81B97F2C7D6447" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_CB3D80F187681A7C1D2FB97F2C7D1253" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0C58DD11A538D08F3F81B97F2C7D6447" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_CB3D80F187681A7C1D2FB97F2C7D1253" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_2CEF14AE48062603BD38B97F2C7D35FC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_CB3D80F187681A7C1D2FB97F2C7D1253" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_2CEF14AE48062603BD38B97F2C7D35FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_21EF9EFB9A9C2CEB57CCB97F2C7D6E2C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_CB3D80F187681A7C1D2FB97F2C7D1253" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_21EF9EFB9A9C2CEB57CCB97F2C7D6E2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_8399D86F57B33AC2F779B97F2C7E01E0" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_CB3D80F187681A7C1D2FB97F2C7D1253" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_8399D86F57B33AC2F779B97F2C7E01E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_728C661B1716861A7FE7B97F2C7E5F7B" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_10433593E74DAF7BD6CFB97F2C7C0BF3" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_728C661B1716861A7FE7B97F2C7E5F7B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_4DC7FA3AA1B3DD65346CB97F2C7EDFE5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_728C661B1716861A7FE7B97F2C7E5F7B" xlink:to="loc_us-gaap_AvailableForSaleSecurities_4DC7FA3AA1B3DD65346CB97F2C7EDFE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_56EB61724F2C0621E748B97F2C7ECA14" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_728C661B1716861A7FE7B97F2C7E5F7B" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_56EB61724F2C0621E748B97F2C7ECA14" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/FinancialInstrumentsAndFairValueInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_FinancialInstrumentsAndFairValueAbstract" xlink:label="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_75ECA87284D2BFC5B603BE9A301EA4D0" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_F1FD99FA726B4B1B72D8BE9A301E4152" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_75ECA87284D2BFC5B603BE9A301EA4D0" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_F1FD99FA726B4B1B72D8BE9A301E4152" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_AADE74742BC764323ED6BE9A301F766F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_F1FD99FA726B4B1B72D8BE9A301E4152" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_AADE74742BC764323ED6BE9A301F766F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_46ABFDAC7FA12A1CB0FFBE9A301F7DB1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_AADE74742BC764323ED6BE9A301F766F" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_46ABFDAC7FA12A1CB0FFBE9A301F7DB1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_6AED2DB6194B6CAB8849BE9A301FA402" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_46ABFDAC7FA12A1CB0FFBE9A301F7DB1" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_6AED2DB6194B6CAB8849BE9A301FA402" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember" xlink:label="loc_us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember_9FD908D9E07399CC4DF5BE9A301FA9A9" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_46ABFDAC7FA12A1CB0FFBE9A301F7DB1" xlink:to="loc_us-gaap_CommercialPaperNotIncludedWithCashAndCashEquivalentsMember_9FD908D9E07399CC4DF5BE9A301FA9A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CertificatesOfDepositMember" xlink:label="loc_us-gaap_CertificatesOfDepositMember_34983BA3F51445759DD1BE9A301F0AA4" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_46ABFDAC7FA12A1CB0FFBE9A301F7DB1" xlink:to="loc_us-gaap_CertificatesOfDepositMember_34983BA3F51445759DD1BE9A301F0AA4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_USTreasuryAndGovernmentMember" xlink:label="loc_us-gaap_USTreasuryAndGovernmentMember_E011B7B35F49A93D88A4BE9A301FEA7D" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_46ABFDAC7FA12A1CB0FFBE9A301F7DB1" xlink:to="loc_us-gaap_USTreasuryAndGovernmentMember_E011B7B35F49A93D88A4BE9A301FEA7D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_USStatesAndPoliticalSubdivisionsMember" xlink:label="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_CB2AAC4CD18433D26BD0BE9A301F2ED1" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_46ABFDAC7FA12A1CB0FFBE9A301F7DB1" xlink:to="loc_us-gaap_USStatesAndPoliticalSubdivisionsMember_CB2AAC4CD18433D26BD0BE9A301F2ED1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_F1FD99FA726B4B1B72D8BE9A301E4152" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses_CE5D0DE0B2BBB1ABA1BEBE9A302401A9" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses_CE5D0DE0B2BBB1ABA1BEBE9A302401A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_DFA8A8B8A741C9A8D246BE9A3024DEFA" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_DFA8A8B8A741C9A8D246BE9A3024DEFA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_83E3FFFCE33EA27CD2F5BE9A3025C85F" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_83E3FFFCE33EA27CD2F5BE9A3025C85F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_FA0C794848844BA6E500BE9A3025733C" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_FA0C794848844BA6E500BE9A3025733C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_02011C1CC7663910075BBE9A302529F0" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_02011C1CC7663910075BBE9A302529F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract_136717A9ACB378768FD5BE9A302571DF" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract_136717A9ACB378768FD5BE9A302571DF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue_56089323EC67E064FB7BBE9A30257038" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract_136717A9ACB378768FD5BE9A302571DF" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue_56089323EC67E064FB7BBE9A30257038" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_620F4F581276EA56ECE3BE9A3025C25B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract_136717A9ACB378768FD5BE9A302571DF" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_620F4F581276EA56ECE3BE9A3025C25B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_009ED2A258B2E1BD9260BE9A3025DC0C" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract_136717A9ACB378768FD5BE9A302571DF" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_009ED2A258B2E1BD9260BE9A3025DC0C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_762426E3FA3FF11F0744BE9A3025E5C2" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract_136717A9ACB378768FD5BE9A302571DF" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_762426E3FA3FF11F0744BE9A3025E5C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_EFAD1BB59B478E97B501BE9A302571F0" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract_136717A9ACB378768FD5BE9A302571DF" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_EFAD1BB59B478E97B501BE9A302571F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_C970B820B50F95A4C653BE9A30255346" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAbstract_136717A9ACB378768FD5BE9A302571DF" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_C970B820B50F95A4C653BE9A30255346" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_35D319F0A67FA746955FBE9A302535D8" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_4FBA262CA134A301BFC1BE9A3024F935" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_35D319F0A67FA746955FBE9A302535D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_F386FA15AFFFADEF9748BE9A3025CB75" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_35D319F0A67FA746955FBE9A302535D8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_F386FA15AFFFADEF9748BE9A3025CB75" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AvailableForSaleSecuritiesDebtMaturitiesAfterOneYearFairValue" xlink:label="loc_ftnt_AvailableForSaleSecuritiesDebtMaturitiesAfterOneYearFairValue_78957E911483FFB921EFBE9A30259227" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_35D319F0A67FA746955FBE9A302535D8" xlink:to="loc_ftnt_AvailableForSaleSecuritiesDebtMaturitiesAfterOneYearFairValue_78957E911483FFB921EFBE9A30259227" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_BD46AA7B3CD4CBA529F3BE9A30250CC5" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesFairValueAbstract_35D319F0A67FA746955FBE9A302535D8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_BD46AA7B3CD4CBA529F3BE9A30250CC5" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/FinancialInstrumentsAndFairValueTables" xlink:type="extended">
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_FinancialInstrumentsAndFairValueAbstract" xlink:label="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_4BDDFAA5BE341996734BBBEB9C644161" xlink:type="locator" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleOfAmortizedCostsUnrealizedGainsAndLossesAndFairValueOfAvailableForSaleSecuritiesTableTextBlock" xlink:label="loc_ftnt_ScheduleOfAmortizedCostsUnrealizedGainsAndLossesAndFairValueOfAvailableForSaleSecuritiesTableTextBlock_CF64A0734AC7D10BF0ACBBEB9C64B872" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_4BDDFAA5BE341996734BBBEB9C644161" xlink:to="loc_ftnt_ScheduleOfAmortizedCostsUnrealizedGainsAndLossesAndFairValueOfAvailableForSaleSecuritiesTableTextBlock_CF64A0734AC7D10BF0ACBBEB9C64B872" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock_4F365D14AC60637C1303BBEB9C649434" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_4BDDFAA5BE341996734BBBEB9C644161" xlink:to="loc_us-gaap_ScheduleOfUnrealizedLossOnInvestmentsTableTextBlock_4F365D14AC60637C1303BBEB9C649434" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock" xlink:label="loc_us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock_BE1E933466B6FED98DB7BBEB9C641977" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_4BDDFAA5BE341996734BBBEB9C644161" xlink:to="loc_us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock_BE1E933466B6FED98DB7BBEB9C641977" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_A9A6B5E7BE36D6C34D53BBEB9C64A1C0" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_FinancialInstrumentsAndFairValueAbstract_4BDDFAA5BE341996734BBBEB9C644161" xlink:to="loc_us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_A9A6B5E7BE36D6C34D53BBEB9C64A1C0" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNet" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_87079A341AA33DC287B4BBEB9C4DF2CA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_3B970B70449A6E26D0ADBBEB9C4DDE24" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_87079A341AA33DC287B4BBEB9C4DF2CA" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureTextBlock_3B970B70449A6E26D0ADBBEB9C4DDE24" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNetEstimatedFutureAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_CA78CD1ADBF1F9555F90B14829EC5265" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_1B78554B3BAA36F4B9A6B14829EC5E02" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_CA78CD1ADBF1F9555F90B14829EC5265" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_1B78554B3BAA36F4B9A6B14829EC5E02" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_83479E18DB894B5CBF9BB14829ECA6CA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_1B78554B3BAA36F4B9A6B14829EC5E02" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_83479E18DB894B5CBF9BB14829ECA6CA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_3995B17CA440DC2D388CB14829ECA31E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_1B78554B3BAA36F4B9A6B14829EC5E02" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_3995B17CA440DC2D388CB14829ECA31E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_1D815AF842227D3136B2B14829ECB6AC" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_1B78554B3BAA36F4B9A6B14829EC5E02" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_1D815AF842227D3136B2B14829ECB6AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_C9FFEBCC5B8D30EA073CB14829EC8DFE" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpenseAbstract_1B78554B3BAA36F4B9A6B14829EC5E02" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_C9FFEBCC5B8D30EA073CB14829EC8DFE" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNetGoodwillDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_B50B05B0A62109BC9D10B61FF2251C76" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_54A8ED707B2B24FB9C71B61FF225083E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_B50B05B0A62109BC9D10B61FF2251C76" xlink:to="loc_us-gaap_Goodwill_54A8ED707B2B24FB9C71B61FF225083E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillImpairmentLoss" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_9B738E2A41943549DFE0B61FF2256411" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_B50B05B0A62109BC9D10B61FF2251C76" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_9B738E2A41943549DFE0B61FF2256411" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNetOtherIntangibleAssetsNetDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_4D1B335D3AAD15C5485CBB42BC7BBE0D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_8DBE506635D38F5F0F0BBB42BC7BE750" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_4D1B335D3AAD15C5485CBB42BC7BBE0D" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_8DBE506635D38F5F0F0BBB42BC7BE750" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_74A6512AECB7E09539D5BB42BC7B6605" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_8DBE506635D38F5F0F0BBB42BC7BE750" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_74A6512AECB7E09539D5BB42BC7B6605" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_D4980769232AFC5EF05CBB42BC7CA33E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_74A6512AECB7E09539D5BB42BC7B6605" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_D4980769232AFC5EF05CBB42BC7CA33E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InProcessResearchAndDevelopmentMember" xlink:label="loc_us-gaap_InProcessResearchAndDevelopmentMember_52414020D36869EAB1E1BB42BC7C13D8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_D4980769232AFC5EF05CBB42BC7CA33E" xlink:to="loc_us-gaap_InProcessResearchAndDevelopmentMember_52414020D36869EAB1E1BB42BC7C13D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_101B045183460C2E8968BB42BC7C2F02" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_8DBE506635D38F5F0F0BBB42BC7BE750" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_101B045183460C2E8968BB42BC7C2F02" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_52CD87A03E563CC952E7BB42BC7C907C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_101B045183460C2E8968BB42BC7C2F02" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_52CD87A03E563CC952E7BB42BC7C907C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DevelopedTechnologyRightsMember" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_C978FB8F279EBEC4B970BB42BC7C0206" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_52CD87A03E563CC952E7BB42BC7C907C" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_C978FB8F279EBEC4B970BB42BC7C0206" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_7294FF13B75E6D6347B0BB42BC7CF9CB" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_52CD87A03E563CC952E7BB42BC7C907C" xlink:to="loc_us-gaap_CustomerRelationshipsMember_7294FF13B75E6D6347B0BB42BC7CF9CB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_28FDEC592A50A95DDDB9BB42BC7CA914" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_8DBE506635D38F5F0F0BBB42BC7BE750" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_28FDEC592A50A95DDDB9BB42BC7CA914" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_E10F74DC9AA6229AD665BB42BC7C4FFD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_28FDEC592A50A95DDDB9BB42BC7CA914" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_E10F74DC9AA6229AD665BB42BC7C4FFD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_CE80EA5614FE547A3054BB42BC7C6530" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_28FDEC592A50A95DDDB9BB42BC7CA914" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_CE80EA5614FE547A3054BB42BC7C6530" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNetAbstract" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_3D896C7C52003C0BE3D0BB42BC7DB8E8" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_28FDEC592A50A95DDDB9BB42BC7CA914" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_3D896C7C52003C0BE3D0BB42BC7DB8E8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_BCB1D341FC02CE80E8BCBB42BC8245F4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_3D896C7C52003C0BE3D0BB42BC7DB8E8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_BCB1D341FC02CE80E8BCBB42BC8245F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_D09F600D669609E38FB6BB42BC823F2F" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_3D896C7C52003C0BE3D0BB42BC7DB8E8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_D09F600D669609E38FB6BB42BC823F2F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_D280F541E9156B048913BB42BC82816B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNetAbstract_3D896C7C52003C0BE3D0BB42BC7DB8E8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_D280F541E9156B048913BB42BC82816B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwillAbstract" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwillAbstract_842192C2A991D229A4ECBB42BC82CBA2" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_28FDEC592A50A95DDDB9BB42BC7CA914" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwillAbstract_842192C2A991D229A4ECBB42BC82CBA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_F02D10817D4112B2D907BB42BC829892" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwillAbstract_842192C2A991D229A4ECBB42BC82CBA2" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_F02D10817D4112B2D907BB42BC829892" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_A31343C04F79EC9F9BABBB42BC8230A8" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_28FDEC592A50A95DDDB9BB42BC7CA914" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_A31343C04F79EC9F9BABBB42BC8230A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_EA63FE804A03BE1435D4BB42BC82CA2B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_A31343C04F79EC9F9BABBB42BC8230A8" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_EA63FE804A03BE1435D4BB42BC82CA2B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_470B98F6B5F42641D9A2BB42BC829C2C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwillAbstract_A31343C04F79EC9F9BABBB42BC8230A8" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_470B98F6B5F42641D9A2BB42BC829C2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_9F7D0117AE25AD1667E7BB42BC826EAC" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_28FDEC592A50A95DDDB9BB42BC7CA914" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_9F7D0117AE25AD1667E7BB42BC826EAC" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/GoodwillAndOtherIntangibleAssetsNetTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_D3E134DC08611E149B25BEB6819D3660" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_3785219A54BFEBAEEC66BEB6819D673E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_D3E134DC08611E149B25BEB6819D3660" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTableTextBlock_3785219A54BFEBAEEC66BEB6819D673E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock" xlink:label="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_C0DCA22F1D973CEF83A9BEB6819D181A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract_D3E134DC08611E149B25BEB6819D3660" xlink:to="loc_us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock_C0DCA22F1D973CEF83A9BEB6819D181A" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/IncomeTaxes" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_1F1D9F88A2EC621CD98DBBEB9BC1ADF9" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="loc_us-gaap_IncomeTaxDisclosureTextBlock_EF3761C085E80840E9D6BBEB9BC17645" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_1F1D9F88A2EC621CD98DBBEB9BC1ADF9" xlink:to="loc_us-gaap_IncomeTaxDisclosureTextBlock_EF3761C085E80840E9D6BBEB9BC17645" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/IncomeTaxesDeferredTaxAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_A0669B1B92364496F66EBAEC099ABB93" xlink:type="locator" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleOfDeferredTaxesTable" xlink:label="loc_ftnt_ScheduleOfDeferredTaxesTable_88AD1BD3208F7CCEC87ABAEC099EA1B7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_A0669B1B92364496F66EBAEC099ABB93" xlink:to="loc_ftnt_ScheduleOfDeferredTaxesTable_88AD1BD3208F7CCEC87ABAEC099EA1B7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_BEFC7314895BF0EDE18DBAEC09A023D6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfDeferredTaxesTable_88AD1BD3208F7CCEC87ABAEC099EA1B7" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_BEFC7314895BF0EDE18DBAEC09A023D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9226B286C780782FC02FBAEC09A09018" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_BEFC7314895BF0EDE18DBAEC09A023D6" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9226B286C780782FC02FBAEC09A09018" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_IncomeTaxesPayableMember" xlink:label="loc_ftnt_IncomeTaxesPayableMember_D525EE4F6CEB1F415DC4BAEC09A13413" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_9226B286C780782FC02FBAEC09A09018" xlink:to="loc_ftnt_IncomeTaxesPayableMember_D525EE4F6CEB1F415DC4BAEC09A13413" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainContingenciesByNatureAxis" xlink:label="loc_us-gaap_GainContingenciesByNatureAxis_F1B4B22C22E81D1140BDBAEC09A12AC9" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfDeferredTaxesTable_88AD1BD3208F7CCEC87ABAEC099EA1B7" xlink:to="loc_us-gaap_GainContingenciesByNatureAxis_F1B4B22C22E81D1140BDBAEC09A12AC9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainContingencyNatureDomain" xlink:label="loc_us-gaap_GainContingencyNatureDomain_DFC63B3FE09DE0D33E0CBAEC09A1DD32" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GainContingenciesByNatureAxis_F1B4B22C22E81D1140BDBAEC09A12AC9" xlink:to="loc_us-gaap_GainContingencyNatureDomain_DFC63B3FE09DE0D33E0CBAEC09A1DD32" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ReductionInTaxesMember" xlink:label="loc_us-gaap_ReductionInTaxesMember_E2FA0E9C09EA9A0F2F29BAEC09A1B612" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_GainContingencyNatureDomain_DFC63B3FE09DE0D33E0CBAEC09A1DD32" xlink:to="loc_us-gaap_ReductionInTaxesMember_E2FA0E9C09EA9A0F2F29BAEC09A1B612" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_819A3A211CBA4FE5B27FBAEC09A2C59C" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfDeferredTaxesTable_88AD1BD3208F7CCEC87ABAEC099EA1B7" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_819A3A211CBA4FE5B27FBAEC09A2C59C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D2D4BF1EAF83C667A556BAEC09A2B290" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_819A3A211CBA4FE5B27FBAEC09A2C59C" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D2D4BF1EAF83C667A556BAEC09A2B290" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_MeruNetworksInc.Member" xlink:label="loc_ftnt_MeruNetworksInc.Member_7156A8DD9A30F4EC47ECBAEC09A24F06" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D2D4BF1EAF83C667A556BAEC09A2B290" xlink:to="loc_ftnt_MeruNetworksInc.Member_7156A8DD9A30F4EC47ECBAEC09A24F06" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AccelOpsInc.Member" xlink:label="loc_ftnt_AccelOpsInc.Member_E3F2280448CC78C31A75BAEC09A28D12" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D2D4BF1EAF83C667A556BAEC09A2B290" xlink:to="loc_ftnt_AccelOpsInc.Member_E3F2280448CC78C31A75BAEC09A28D12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_BE0599B1F8FA6ED66D5DBAEC09A2DC3A" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfDeferredTaxesTable_88AD1BD3208F7CCEC87ABAEC099EA1B7" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_BE0599B1F8FA6ED66D5DBAEC09A2DC3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_EED41BEE4B2C7D23A8B4BAEC09A21AB8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_BE0599B1F8FA6ED66D5DBAEC09A2DC3A" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_EED41BEE4B2C7D23A8B4BAEC09A21AB8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="loc_us-gaap_ForeignCountryMember_CDCB5E0F81673933681EBAEC09A21D23" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_EED41BEE4B2C7D23A8B4BAEC09A21AB8" xlink:to="loc_us-gaap_ForeignCountryMember_CDCB5E0F81673933681EBAEC09A21D23" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DomesticCountryMember" xlink:label="loc_us-gaap_DomesticCountryMember_ABDF8C3C754360D52E80BAEC09A25520" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_EED41BEE4B2C7D23A8B4BAEC09A21AB8" xlink:to="loc_us-gaap_DomesticCountryMember_ABDF8C3C754360D52E80BAEC09A25520" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StateAndLocalJurisdictionMember" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_CF0B2B37F925A40BE3E0BAEC09A2DBCD" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_EED41BEE4B2C7D23A8B4BAEC09A21AB8" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_CF0B2B37F925A40BE3E0BAEC09A2DBCD" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_StateJurisdictionCaliforniaMember" xlink:label="loc_ftnt_StateJurisdictionCaliforniaMember_EF0ACC16218701908DA6BAEC09A2217A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StateAndLocalJurisdictionMember_CF0B2B37F925A40BE3E0BAEC09A2DBCD" xlink:to="loc_ftnt_StateJurisdictionCaliforniaMember_EF0ACC16218701908DA6BAEC09A2217A" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_DeferredTaxesLineItems" xlink:label="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfDeferredTaxesTable_88AD1BD3208F7CCEC87ABAEC099EA1B7" xlink:to="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation_0A0B840AD1ADCA396AC1BAEC09A3CCC0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation_0A0B840AD1ADCA396AC1BAEC09A3CCC0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignEarningsRepatriated" xlink:label="loc_us-gaap_ForeignEarningsRepatriated_F8EF01097D88BA43ECCEBAEC09A3DC6D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_us-gaap_ForeignEarningsRepatriated_F8EF01097D88BA43ECCEBAEC09A3DC6D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationRepatriationOfForeignEarnings" xlink:label="loc_us-gaap_IncomeTaxReconciliationRepatriationOfForeignEarnings_561C63CC37A63614094BBAEC09A30266" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_us-gaap_IncomeTaxReconciliationRepatriationOfForeignEarnings_561C63CC37A63614094BBAEC09A30266" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComponentsOfDeferredTaxAssetsAbstract" xlink:label="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness_23B67C1988EFA8010647BAEC09A3F78C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness_23B67C1988EFA8010647BAEC09A3F78C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsDeferredIncome" xlink:label="loc_us-gaap_DeferredTaxAssetsDeferredIncome_7BF2202C37BEA4B7C9B0BAEC09A71300" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:to="loc_us-gaap_DeferredTaxAssetsDeferredIncome_7BF2202C37BEA4B7C9B0BAEC09A71300" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_5A401BE70E3405B20C8FBAEC09A73074" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals_5A401BE70E3405B20C8FBAEC09A73074" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_67B47773377DCDC90919BAEC09A7233D" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwards_67B47773377DCDC90919BAEC09A7233D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_0CC7C31D4F9D6D46D352BAEC09A700D4" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost_0CC7C31D4F9D6D46D352BAEC09A700D4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment" xlink:label="loc_us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment_854D6FC885C556825DDDBAEC09A7CD5A" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:to="loc_us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment_854D6FC885C556825DDDBAEC09A7CD5A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="loc_us-gaap_DeferredTaxAssetsOther_B692F855B64B3C60982FBAEC09A7AFDC" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:to="loc_us-gaap_DeferredTaxAssetsOther_B692F855B64B3C60982FBAEC09A7AFDC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="loc_us-gaap_DeferredTaxAssetsNet_CCAF79C5F00DCE685709BAEC09A7483A" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ComponentsOfDeferredTaxAssetsAbstract_B0F4D421F98649D91B4BBAEC09A3FD9C" xlink:to="loc_us-gaap_DeferredTaxAssetsNet_CCAF79C5F00DCE685709BAEC09A7483A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLossCarryforwards" xlink:label="loc_us-gaap_OperatingLossCarryforwards_22BDC7011F20AF7C1BB3BAEC09A73D10" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_us-gaap_OperatingLossCarryforwards_22BDC7011F20AF7C1BB3BAEC09A73D10" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TaxCreditCarryforwardAmount" xlink:label="loc_us-gaap_TaxCreditCarryforwardAmount_1FE0FA07EAE41E1BE613BAEC09A78742" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_us-gaap_TaxCreditCarryforwardAmount_1FE0FA07EAE41E1BE613BAEC09A78742" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_F774D12F62675CA04713BAEC09A702C5" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_F774D12F62675CA04713BAEC09A702C5" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_CanadianDeemedDividendDistribution" xlink:label="loc_ftnt_CanadianDeemedDividendDistribution_4881524AB71B085E4E33BAEC09A7B98B" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_ftnt_CanadianDeemedDividendDistribution_4881524AB71B085E4E33BAEC09A7B98B" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EffectiveIncomeTaxRateReconciliationCanadianDeemedDividendDistribution" xlink:label="loc_ftnt_EffectiveIncomeTaxRateReconciliationCanadianDeemedDividendDistribution_3729F969686B622D3E36BAEC09A70C92" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_ftnt_EffectiveIncomeTaxRateReconciliationCanadianDeemedDividendDistribution_3729F969686B622D3E36BAEC09A70C92" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_IncometaxExpenseBenefitDeferredTaxBenefitCanadianStockBasedCompensationExpense" xlink:label="loc_ftnt_IncometaxExpenseBenefitDeferredTaxBenefitCanadianStockBasedCompensationExpense_D5895AB9378A4DA3B95DBAEC09A72284" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_DeferredTaxesLineItems_50E1496834B154709E64BAEC09A3FB38" xlink:to="loc_ftnt_IncometaxExpenseBenefitDeferredTaxBenefitCanadianStockBasedCompensationExpense_D5895AB9378A4DA3B95DBAEC09A72284" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/IncomeTaxesEffectiveTaxRateReconciliationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:label="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_559A6096EB602F76AD06B5D760782D8D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_559A6096EB602F76AD06B5D760782D8D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential" xlink:label="loc_us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential_BC344D8FA2AB61F3A14AB5D76078EED5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential_BC344D8FA2AB61F3A14AB5D76078EED5" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EffectiveIncomeTaxRateReconciliationForeignWithholdingTaxesAmount" xlink:label="loc_ftnt_EffectiveIncomeTaxRateReconciliationForeignWithholdingTaxesAmount_AAB2E2BC3DB2CEB9C573B5D760784B4B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_ftnt_EffectiveIncomeTaxRateReconciliationForeignWithholdingTaxesAmount_AAB2E2BC3DB2CEB9C573B5D760784B4B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:label="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost_CD509B7287E8F835EDF1B5D760783D6E" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost_CD509B7287E8F835EDF1B5D760783D6E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationTaxCreditsForeign" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxCreditsForeign_0DC812E4C29A667B8E3BB5D7607860DB" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxCreditsForeign_0DC812E4C29A667B8E3BB5D7607860DB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_7E6226304F28297D233FB5D7607897F8" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_7E6226304F28297D233FB5D7607897F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationTaxCreditsResearch" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxCreditsResearch_B6A6F68224F15D81ADDCB5D76078A930" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxCreditsResearch_B6A6F68224F15D81ADDCB5D76078A930" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EffectiveIncomeTaxRateReconciliationCanadianDeemedDividendDistribution" xlink:label="loc_ftnt_EffectiveIncomeTaxRateReconciliationCanadianDeemedDividendDistribution_861E900E7932DFAFD15AB5D760781D4E" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_ftnt_EffectiveIncomeTaxRateReconciliationCanadianDeemedDividendDistribution_861E900E7932DFAFD15AB5D760781D4E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate" xlink:label="loc_us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate_061300943A7FBE0F8C0EB6351114447D" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate_061300943A7FBE0F8C0EB6351114447D" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EffectiveIncomeTaxRateReconciliationTaxCutsandJobsActof2017TransitionTaxonAccumulatedForeignEarningsAmount" xlink:label="loc_ftnt_EffectiveIncomeTaxRateReconciliationTaxCutsandJobsActof2017TransitionTaxonAccumulatedForeignEarningsAmount_8BA92E07915D96CCD204B636C3D7CA58" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_ftnt_EffectiveIncomeTaxRateReconciliationTaxCutsandJobsActof2017TransitionTaxonAccumulatedForeignEarningsAmount_8BA92E07915D96CCD204B636C3D7CA58" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxReconciliationOtherAdjustments" xlink:label="loc_us-gaap_IncomeTaxReconciliationOtherAdjustments_CD5D53D60595702CA3AFB5D760788B48" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxReconciliationOtherAdjustments_CD5D53D60595702CA3AFB5D760788B48" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_BE3613FEB3DDA19FE9AAB5D760782CC6" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_7F8FF313F47164F24A2EB5D76077B0FC" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_BE3613FEB3DDA19FE9AAB5D760782CC6" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/IncomeTaxesProvisionForIncomeTaxDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_231374560E34E6A01E02BEE1FDD4415B" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_2B25B97AF20EFCE8119FBEE1FDD65BD5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_231374560E34E6A01E02BEE1FDD4415B" xlink:to="loc_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_2B25B97AF20EFCE8119FBEE1FDD65BD5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentFederalTaxExpenseBenefit_C7E621DC10B55A0B02CABEE1FDD63E50" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_2B25B97AF20EFCE8119FBEE1FDD65BD5" xlink:to="loc_us-gaap_CurrentFederalTaxExpenseBenefit_C7E621DC10B55A0B02CABEE1FDD63E50" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_CDD76EB3ED145A8243B9BEE1FDD6444B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_2B25B97AF20EFCE8119FBEE1FDD65BD5" xlink:to="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_CDD76EB3ED145A8243B9BEE1FDD6444B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentForeignTaxExpenseBenefit_E4D180D6F97CC0D64708BEE1FDD66FD8" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_2B25B97AF20EFCE8119FBEE1FDD65BD5" xlink:to="loc_us-gaap_CurrentForeignTaxExpenseBenefit_E4D180D6F97CC0D64708BEE1FDD66FD8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_98E5B64AC743E354E935BEE1FDD787E1" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefitContinuingOperationsAbstract_2B25B97AF20EFCE8119FBEE1FDD65BD5" xlink:to="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_98E5B64AC743E354E935BEE1FDD787E1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_04215883D1F085162C00BEE1FDD76CE5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_231374560E34E6A01E02BEE1FDD4415B" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_04215883D1F085162C00BEE1FDD76CE5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_89DB319303BF34AC57E5BEE1FDD7F72B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_04215883D1F085162C00BEE1FDD76CE5" xlink:to="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_89DB319303BF34AC57E5BEE1FDD7F72B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_397449D6D941704D5616BEE1FDD781AE" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_04215883D1F085162C00BEE1FDD76CE5" xlink:to="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_397449D6D941704D5616BEE1FDD781AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_E92248C1E85694D14BC3BEE1FDD7E8F6" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_04215883D1F085162C00BEE1FDD76CE5" xlink:to="loc_us-gaap_DeferredForeignIncomeTaxExpenseBenefit_E92248C1E85694D14BC3BEE1FDD7E8F6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_90BE07244776505413A8BEE1FDD7CCFF" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefitContinuingOperationsAbstract_04215883D1F085162C00BEE1FDD76CE5" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_90BE07244776505413A8BEE1FDD7CCFF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_AC66AAD0E0C7CC2A8734BEE1FDD86393" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_231374560E34E6A01E02BEE1FDD4415B" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_AC66AAD0E0C7CC2A8734BEE1FDD86393" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/IncomeTaxesReconciliationOfPreTaxIncomedetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_90396CB68AED3A45DA49BBEB9C1A1059" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAbstract" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAbstract_C41AC084F96F334917BEBBEB9C1AE6AC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_90396CB68AED3A45DA49BBEB9C1A1059" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAbstract_C41AC084F96F334917BEBBEB9C1AE6AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_3BC25E0C91054C293634BBEB9C1A61BF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAbstract_C41AC084F96F334917BEBBEB9C1AE6AC" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic_3BC25E0C91054C293634BBEB9C1A61BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_3A054F59750C247FEBF4BBEB9C1AEDEE" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAbstract_C41AC084F96F334917BEBBEB9C1AE6AC" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign_3A054F59750C247FEBF4BBEB9C1AEDEE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_23C326A9DAC206DBDAC0BBEB9C1A5011" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestmentsAbstract_C41AC084F96F334917BEBBEB9C1AE6AC" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_23C326A9DAC206DBDAC0BBEB9C1A5011" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/IncomeTaxesTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_0A4F6C65F3582B0F599ABBEB9C2B7F00" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock_96747DAD69D366856DA6BBEB9C2B1916" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_0A4F6C65F3582B0F599ABBEB9C2B7F00" xlink:to="loc_us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock_96747DAD69D366856DA6BBEB9C2B1916" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_342364F6935F797423C2BBEB9C2C6D34" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_0A4F6C65F3582B0F599ABBEB9C2B7F00" xlink:to="loc_us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock_342364F6935F797423C2BBEB9C2C6D34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_E944FCF15D638C596741BBEB9C2C635D" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_0A4F6C65F3582B0F599ABBEB9C2B7F00" xlink:to="loc_us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock_E944FCF15D638C596741BBEB9C2C635D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_FECEBC228CD0CF5EA3BEBBEB9C2CACF7" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_0A4F6C65F3582B0F599ABBEB9C2B7F00" xlink:to="loc_us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock_FECEBC228CD0CF5EA3BEBBEB9C2CACF7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_E0AD21600A6CC4563277BBEB9C2CB5FD" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_0A4F6C65F3582B0F599ABBEB9C2B7F00" xlink:to="loc_us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock_E0AD21600A6CC4563277BBEB9C2CB5FD" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/IncomeTaxesTcjaNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_C51AC91514F39A54130EB646707D2C42" xlink:type="locator" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EffectiveIncomeTaxRateReconciliationSharebasedCompensationExcessTaxBenefitAmount" xlink:label="loc_ftnt_EffectiveIncomeTaxRateReconciliationSharebasedCompensationExcessTaxBenefitAmount_A458BC3A9B0276E7A0ACB64D67553882" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_C51AC91514F39A54130EB646707D2C42" xlink:to="loc_ftnt_EffectiveIncomeTaxRateReconciliationSharebasedCompensationExcessTaxBenefitAmount_A458BC3A9B0276E7A0ACB64D67553882" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_TaxCutsandJobsActof2017IncompleteAccountingChangeinTaxRateDeferredTaxAssetProvisionalIncomeTaxExpense" xlink:label="loc_ftnt_TaxCutsandJobsActof2017IncompleteAccountingChangeinTaxRateDeferredTaxAssetProvisionalIncomeTaxExpense_EC708B2CAFB659566D4EB6471AEAA66A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_C51AC91514F39A54130EB646707D2C42" xlink:to="loc_ftnt_TaxCutsandJobsActof2017IncompleteAccountingChangeinTaxRateDeferredTaxAssetProvisionalIncomeTaxExpense_EC708B2CAFB659566D4EB6471AEAA66A" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_TaxCutsandJobsActof2017IncompleteAccountingTransitionTaxforAccumulatedForeignEarningsProvisionalIncomeTaxExpense" xlink:label="loc_ftnt_TaxCutsandJobsActof2017IncompleteAccountingTransitionTaxforAccumulatedForeignEarningsProvisionalIncomeTaxExpense_D655A3149A3A5A9593C3B6489F24428B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_C51AC91514F39A54130EB646707D2C42" xlink:to="loc_ftnt_TaxCutsandJobsActof2017IncompleteAccountingTransitionTaxforAccumulatedForeignEarningsProvisionalIncomeTaxExpense_D655A3149A3A5A9593C3B6489F24428B" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/IncomeTaxesUnrecognizedTaxBenefitsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_1B80898D91D3ACD4798ABEE2019546F4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxContingencyTable" xlink:label="loc_us-gaap_IncomeTaxContingencyTable_681E1A308F25F05CD58FBEE20196A7CE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_1B80898D91D3ACD4798ABEE2019546F4" xlink:to="loc_us-gaap_IncomeTaxContingencyTable_681E1A308F25F05CD58FBEE20196A7CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_912868FCBBF9A9B721FEBEE51DD7DE68" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_681E1A308F25F05CD58FBEE20196A7CE" xlink:to="loc_us-gaap_StatementScenarioAxis_912868FCBBF9A9B721FEBEE51DD7DE68" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_1B7A9E80F20414B18046BEE5224AD48C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementScenarioAxis_912868FCBBF9A9B721FEBEE51DD7DE68" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_1B7A9E80F20414B18046BEE5224AD48C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioForecastMember" xlink:label="loc_us-gaap_ScenarioForecastMember_6CBAD1B421761B60E2BABEE51F4367AC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_1B7A9E80F20414B18046BEE5224AD48C" xlink:to="loc_us-gaap_ScenarioForecastMember_6CBAD1B421761B60E2BABEE51F4367AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_1AF13E3A470B109DC338BEE20196BA93" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_681E1A308F25F05CD58FBEE20196A7CE" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_1AF13E3A470B109DC338BEE20196BA93" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_F8B7B9D32BD49BA75780BEE201963504" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1AF13E3A470B109DC338BEE20196BA93" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_F8B7B9D32BD49BA75780BEE201963504" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_92A8BEB2A1CFF837BDEBBEE201973CF9" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_F8B7B9D32BD49BA75780BEE201963504" xlink:to="loc_us-gaap_SubsequentEventMember_92A8BEB2A1CFF837BDEBBEE201973CF9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_E7F8A51A8EF4660A8E43BEE201970194" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_681E1A308F25F05CD58FBEE20196A7CE" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_E7F8A51A8EF4660A8E43BEE201970194" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_1F585364095EB9686B01BEE20197F0BC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_E7F8A51A8EF4660A8E43BEE201970194" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_1F585364095EB9686B01BEE20197F0BC" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_IncomeTaxLiabilitiesNoncurrentMember" xlink:label="loc_ftnt_IncomeTaxLiabilitiesNoncurrentMember_378E5D311819ACE1068BBEE20197E962" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_1F585364095EB9686B01BEE20197F0BC" xlink:to="loc_ftnt_IncomeTaxLiabilitiesNoncurrentMember_378E5D311819ACE1068BBEE20197E962" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxContingencyLineItems" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_681E1A308F25F05CD58FBEE20196A7CE" xlink:to="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_B9AC3776F7B4404C6935BEE201975518" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_B9AC3776F7B4404C6935BEE201975518" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_A4DB4E79DB1F58A93DE7BEE201981CED" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_A4DB4E79DB1F58A93DE7BEE201981CED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward" xlink:label="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:to="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_7317D8C9F0BBFEBD69BCBEE201980B9C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_7317D8C9F0BBFEBD69BCBEE201980B9C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_4F6B8878451D59AB14ACBEE20198C46E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions_4F6B8878451D59AB14ACBEE20198C46E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions_8BEEE3D95481DDA70F63BEE20198F618" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions_8BEEE3D95481DDA70F63BEE20198F618" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_DF684F8AAB2C86F46ED9BEE2019836B5" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_DF684F8AAB2C86F46ED9BEE2019836B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_2DE0193EFACCA62370EDBEE20198BB11" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_2DE0193EFACCA62370EDBEE20198BB11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_EC801B942470B3FD5A8DBEE201987019" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations_EC801B942470B3FD5A8DBEE201987019" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_02DE882A7CA8291D379BBEE20199169C" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ReconciliationOfUnrecognizedTaxBenefitsExcludingAmountsPertainingToExaminedTaxReturnsRollForward_F988722EB8A8E72A2AB9BEE20198B6C6" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_02DE882A7CA8291D379BBEE20199169C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilityForUncertainTaxPositionsNoncurrent" xlink:label="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_B9BE3CF049B37A4DDE75BEE201997209" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:to="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_B9BE3CF049B37A4DDE75BEE201997209" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit_9C9177CBB77788E59C4FBEE201991D0C" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit_9C9177CBB77788E59C4FBEE201991D0C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority" xlink:label="loc_us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority_4B32A59900BB6FDA7CC7BEE201995A12" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:to="loc_us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority_4B32A59900BB6FDA7CC7BEE201995A12" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_DE8A4E35ACA655CF48EABEE51B90257A" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_140049CB65210EBBAF42BEE201973CC5" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_DE8A4E35ACA655CF48EABEE51B90257A" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/Inventory" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="loc_us-gaap_InventoryDisclosureAbstract_813895A23B684BA74066BBEB9BF88FF8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="loc_us-gaap_InventoryDisclosureTextBlock_54EA17EF2275025B984EBBEB9BF89D16" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_813895A23B684BA74066BBEB9BF88FF8" xlink:to="loc_us-gaap_InventoryDisclosureTextBlock_54EA17EF2275025B984EBBEB9BF89D16" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/InventoryDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="loc_us-gaap_InventoryDisclosureAbstract_A6A9B486EEB603C20E3ABBEB9C305C52" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryNetAbstract" xlink:label="loc_us-gaap_InventoryNetAbstract_C6F1C7A36D2EEA7699DABBEB9C30AF40" xlink:type="locator" />
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_A6A9B486EEB603C20E3ABBEB9C305C52" xlink:to="loc_us-gaap_InventoryNetAbstract_C6F1C7A36D2EEA7699DABBEB9C30AF40" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryRawMaterialsNetOfReserves" xlink:label="loc_us-gaap_InventoryRawMaterialsNetOfReserves_2623D9792FE4A5028720BBEB9C302DBB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryNetAbstract_C6F1C7A36D2EEA7699DABBEB9C30AF40" xlink:to="loc_us-gaap_InventoryRawMaterialsNetOfReserves_2623D9792FE4A5028720BBEB9C302DBB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:label="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_06B7A66B0BD9D765E89ABBEB9C30EBCE" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryNetAbstract_C6F1C7A36D2EEA7699DABBEB9C30AF40" xlink:to="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_06B7A66B0BD9D765E89ABBEB9C30EBCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_921656D58C099B50BEDDBBEB9C30CD2A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryNetAbstract_C6F1C7A36D2EEA7699DABBEB9C30AF40" xlink:to="loc_us-gaap_InventoryNet_921656D58C099B50BEDDBBEB9C30CD2A" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_InventoryFinishedGoodsNetofReservesHeldbyDistributors" xlink:label="loc_ftnt_InventoryFinishedGoodsNetofReservesHeldbyDistributors_ADF895A5CB8C15356F83BBEB9C302A0E" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryNetAbstract_C6F1C7A36D2EEA7699DABBEB9C30AF40" xlink:to="loc_ftnt_InventoryFinishedGoodsNetofReservesHeldbyDistributors_ADF895A5CB8C15356F83BBEB9C302A0E" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_InventoryRawMaterialsNetofReservesatContractManufacturers" xlink:label="loc_ftnt_InventoryRawMaterialsNetofReservesatContractManufacturers_9F072181CFDE76AC22BBBBEB9C30779E" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryNetAbstract_C6F1C7A36D2EEA7699DABBEB9C30AF40" xlink:to="loc_ftnt_InventoryRawMaterialsNetofReservesatContractManufacturers_9F072181CFDE76AC22BBBBEB9C30779E" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/InventoryTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="loc_us-gaap_InventoryDisclosureAbstract_85FADB118B761860E6A1BBEB9C616D48" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfInventoryCurrentTableTextBlock_CA9103782863D7810AA6BBEB9C612D1C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_85FADB118B761860E6A1BBEB9C616D48" xlink:to="loc_us-gaap_ScheduleOfInventoryCurrentTableTextBlock_CA9103782863D7810AA6BBEB9C612D1C" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/InvestmentsInPrivatelyHeldCompanies" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InvestmentsAllOtherInvestmentsAbstract" xlink:label="loc_us-gaap_InvestmentsAllOtherInvestmentsAbstract_3D85A9838D2E0BDEACFCBBEB9BFDCD7E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostMethodInvestmentsDescriptionTextBlock" xlink:label="loc_us-gaap_CostMethodInvestmentsDescriptionTextBlock_194659522D74033216BDBBEB9BFD223C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InvestmentsAllOtherInvestmentsAbstract_3D85A9838D2E0BDEACFCBBEB9BFDCD7E" xlink:to="loc_us-gaap_CostMethodInvestmentsDescriptionTextBlock_194659522D74033216BDBBEB9BFD223C" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/InvestmentsInPrivatelyHeldCompaniesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InvestmentsAllOtherInvestmentsAbstract" xlink:label="loc_us-gaap_InvestmentsAllOtherInvestmentsAbstract_E65716880D978B8F5350B5D7631309BF" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostMethodInvestmentsOriginalCost" xlink:label="loc_us-gaap_CostMethodInvestmentsOriginalCost_5CD5D31815513C3CFBF9B5D76314C9BD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InvestmentsAllOtherInvestmentsAbstract_E65716880D978B8F5350B5D7631309BF" xlink:to="loc_us-gaap_CostMethodInvestmentsOriginalCost_5CD5D31815513C3CFBF9B5D76314C9BD" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/NetIncomePerShare" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_69F374DDAA43EAF31B0BBBEB9AF63746" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="loc_us-gaap_EarningsPerShareTextBlock_98C0728C1984CA79F9CEBBEB9AF71FAF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_69F374DDAA43EAF31B0BBBEB9AF63746" xlink:to="loc_us-gaap_EarningsPerShareTextBlock_98C0728C1984CA79F9CEBBEB9AF71FAF" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/NetIncomePerShareAntiDilutiveSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_0E7FAEA8F1721A11C36CBBEB9C1E58F3" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_1D0AC04AA5CFE4C02BD8BBEB9C1FB6EA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_0E7FAEA8F1721A11C36CBBEB9C1E58F3" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_1D0AC04AA5CFE4C02BD8BBEB9C1FB6EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_16A25F757772B72D39B2BBEB9C1F3988" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_1D0AC04AA5CFE4C02BD8BBEB9C1FB6EA" xlink:to="loc_us-gaap_AwardTypeAxis_16A25F757772B72D39B2BBEB9C1F3988" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0721286B55ED4E7C923BBBEB9C1F87E0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_16A25F757772B72D39B2BBEB9C1F3988" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0721286B55ED4E7C923BBBEB9C1F87E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_5A0B22A0776C8EDAEE40BBEB9C1F152A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0721286B55ED4E7C923BBBEB9C1F87E0" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_5A0B22A0776C8EDAEE40BBEB9C1F152A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_B5C5B879FF4FB25675C3BBEB9C1F9580" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0721286B55ED4E7C923BBBEB9C1F87E0" xlink:to="loc_us-gaap_EmployeeStockOptionMember_B5C5B879FF4FB25675C3BBEB9C1F9580" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeStockMember" xlink:label="loc_us-gaap_EmployeeStockMember_34D081FADA1BFF263FF9BBEB9C1FD8F7" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0721286B55ED4E7C923BBBEB9C1F87E0" xlink:to="loc_us-gaap_EmployeeStockMember_34D081FADA1BFF263FF9BBEB9C1FD8F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_D59FE50DBDE3FCCFE5B6BBEB9C1F995D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_1D0AC04AA5CFE4C02BD8BBEB9C1FB6EA" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_D59FE50DBDE3FCCFE5B6BBEB9C1F995D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_EFB94DEB7054E02FA33FBBEB9C1F32A7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_D59FE50DBDE3FCCFE5B6BBEB9C1F995D" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_EFB94DEB7054E02FA33FBBEB9C1F32A7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockCompensationPlanMember" xlink:label="loc_us-gaap_StockCompensationPlanMember_153C7913A194636C1BF4BBEB9C1F3495" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_EFB94DEB7054E02FA33FBBEB9C1F32A7" xlink:to="loc_us-gaap_StockCompensationPlanMember_153C7913A194636C1BF4BBEB9C1F3495" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_3814162593CE038B67C7BBEB9C1F18A4" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_1D0AC04AA5CFE4C02BD8BBEB9C1FB6EA" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_3814162593CE038B67C7BBEB9C1F18A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_7A85CD54641EFE8B8D4EBBEB9C1FD976" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_3814162593CE038B67C7BBEB9C1F18A4" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_7A85CD54641EFE8B8D4EBBEB9C1FD976" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/NetIncomePerShareCalculationOfBasicAndDilutedDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_4A8B86E3078D4D886FC6BBEB9C453DB7" xlink:type="locator" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleOfEarningsPerShareTable" xlink:label="loc_ftnt_ScheduleOfEarningsPerShareTable_0E263735F8F56EB19F25BBEB9C453298" xlink:type="locator" />
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_4A8B86E3078D4D886FC6BBEB9C453DB7" xlink:to="loc_ftnt_ScheduleOfEarningsPerShareTable_0E263735F8F56EB19F25BBEB9C453298" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_0A76668EBDD2641056A7BBEB9C45504D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfEarningsPerShareTable_0E263735F8F56EB19F25BBEB9C453298" xlink:to="loc_us-gaap_AwardTypeAxis_0A76668EBDD2641056A7BBEB9C45504D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5DA1EC061835B37A611DBBEB9C45AA4A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_0A76668EBDD2641056A7BBEB9C45504D" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5DA1EC061835B37A611DBBEB9C45AA4A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_C0C8D5AEDC121230F010BBEB9C45C8DE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5DA1EC061835B37A611DBBEB9C45AA4A" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_C0C8D5AEDC121230F010BBEB9C45C8DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_F6679315D94C05DF966DBBEB9C4527C5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5DA1EC061835B37A611DBBEB9C45AA4A" xlink:to="loc_us-gaap_EmployeeStockOptionMember_F6679315D94C05DF966DBBEB9C4527C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeStockMember" xlink:label="loc_us-gaap_EmployeeStockMember_BC904DE250EFD37DC7C4BBEB9C45E57A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5DA1EC061835B37A611DBBEB9C45AA4A" xlink:to="loc_us-gaap_EmployeeStockMember_BC904DE250EFD37DC7C4BBEB9C45E57A" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EarningsPerShareLineItems" xlink:label="loc_ftnt_EarningsPerShareLineItems_4194C9DF2A58445E17DDBBEB9C45E291" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfEarningsPerShareTable_0E263735F8F56EB19F25BBEB9C453298" xlink:to="loc_ftnt_EarningsPerShareLineItems_4194C9DF2A58445E17DDBBEB9C45E291" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_FDA267A94A4D7D843BE9BBEB9C45D234" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_EarningsPerShareLineItems_4194C9DF2A58445E17DDBBEB9C45E291" xlink:to="loc_us-gaap_NetIncomeLoss_FDA267A94A4D7D843BE9BBEB9C45D234" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_42851B03533DA9951CB1BBEB9C462BD6" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_EarningsPerShareLineItems_4194C9DF2A58445E17DDBBEB9C45E291" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_42851B03533DA9951CB1BBEB9C462BD6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_03DB09B8EC875ACF6E73BBEB9C46DDE9" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasicAbstract_42851B03533DA9951CB1BBEB9C462BD6" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_03DB09B8EC875ACF6E73BBEB9C46DDE9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_D8D3F15DD8D704C2BDB1BBEB9C4644C0" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_EarningsPerShareLineItems_4194C9DF2A58445E17DDBBEB9C45E291" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_D8D3F15DD8D704C2BDB1BBEB9C4644C0" xlink:type="arc" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_D8D3F15DD8D704C2BDB1BBEB9C4644C0" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_03DB09B8EC875ACF6E73BBEB9C46DDE9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_018EADDE1B6069E1D1C8BBEB9C46649A" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_EarningsPerShareLineItems_4194C9DF2A58445E17DDBBEB9C45E291" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_018EADDE1B6069E1D1C8BBEB9C46649A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_19635B001BF66ECBE1ADBBEB9C460EB0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_018EADDE1B6069E1D1C8BBEB9C46649A" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_19635B001BF66ECBE1ADBBEB9C460EB0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_F96B43BBFDA09BE7F186BBEB9C469C90" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_018EADDE1B6069E1D1C8BBEB9C46649A" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_F96B43BBFDA09BE7F186BBEB9C469C90" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_2EC80009C75D337D9013BBEB9C46B267" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_EarningsPerShareLineItems_4194C9DF2A58445E17DDBBEB9C45E291" xlink:to="loc_us-gaap_EarningsPerShareBasic_2EC80009C75D337D9013BBEB9C46B267" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_428932493ED9529F60ADBBEB9C4678DC" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_EarningsPerShareLineItems_4194C9DF2A58445E17DDBBEB9C45E291" xlink:to="loc_us-gaap_EarningsPerShareDiluted_428932493ED9529F60ADBBEB9C4678DC" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/NetIncomePerShareTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_0D0DBA1F54B27C50C74EBBEB9C0BDB13" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_0A18D55592A697C9A7D8BBEB9C0BF6D1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_0D0DBA1F54B27C50C74EBBEB9C0BDB13" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_0A18D55592A697C9A7D8BBEB9C0BF6D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_74BEF73CCD44C2D3ADAEBBEB9C0C054D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_0D0DBA1F54B27C50C74EBBEB9C0BDB13" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_74BEF73CCD44C2D3ADAEBBEB9C0C054D" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/PropertyAndEquipmentnet" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAbstract_035CE55D77FDD286D80DBBEB9CDF54E1" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_C80BFA40F1C554FECDC1BBEB9CDF5AAB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract_035CE55D77FDD286D80DBBEB9CDF54E1" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_C80BFA40F1C554FECDC1BBEB9CDF5AAB" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/PropertyAndEquipmentnetDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAbstract_715B34DF9EDB51845540B5D7632CD7E4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_038CF01516D2D7B97C9DB5D7632C9B51" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract_715B34DF9EDB51845540B5D7632CD7E4" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_038CF01516D2D7B97C9DB5D7632C9B51" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5EF6076DC71E4BB61547B5D7632CE794" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_038CF01516D2D7B97C9DB5D7632C9B51" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5EF6076DC71E4BB61547B5D7632CE794" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5EF6076DC71E4BB61547B5D7632CE794" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_9E82D0702CF0889EA725B5D7632DC9DB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_9E82D0702CF0889EA725B5D7632DC9DB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:label="loc_us-gaap_ComputerEquipmentMember_67C31E3090B68C106788B5D7632D9B83" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_us-gaap_ComputerEquipmentMember_67C31E3090B68C106788B5D7632D9B83" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LandMember" xlink:label="loc_us-gaap_LandMember_D877777A788A2EA73981B5D7632D2598" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_us-gaap_LandMember_D877777A788A2EA73981B5D7632D2598" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LeaseholdsAndLeaseholdImprovementsMember" xlink:label="loc_us-gaap_LeaseholdsAndLeaseholdImprovementsMember_15F9B8CEF86DBAB5A6CFB5D7632DFBE3" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_us-gaap_LeaseholdsAndLeaseholdImprovementsMember_15F9B8CEF86DBAB5A6CFB5D7632DFBE3" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EvaluationUnitsMember" xlink:label="loc_ftnt_EvaluationUnitsMember_20FCA379C051A1FA9391B5D7632D0D5A" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_ftnt_EvaluationUnitsMember_20FCA379C051A1FA9391B5D7632D0D5A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_5FE1BBA73E10260C21C9B5D7632DD2CD" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_5FE1BBA73E10260C21C9B5D7632DD2CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConstructionInProgressMember" xlink:label="loc_us-gaap_ConstructionInProgressMember_DE814101081482EA5924B5D7632D4982" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_us-gaap_ConstructionInProgressMember_DE814101081482EA5924B5D7632D4982" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LandAndBuildingMember" xlink:label="loc_us-gaap_LandAndBuildingMember_9485ADA341CE655AA6ADB5D7632D385A" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_us-gaap_LandAndBuildingMember_9485ADA341CE655AA6ADB5D7632D385A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_80E08531AB751792FA9EB5D7632DD6FB" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FD091224C23F01CC84CBB5D7632DC72D" xlink:to="loc_us-gaap_BuildingMember_80E08531AB751792FA9EB5D7632DD6FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_61C1740721D4ED1D5962B5D7632E21B2" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_038CF01516D2D7B97C9DB5D7632C9B51" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentLineItems_61C1740721D4ED1D5962B5D7632E21B2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_08572DF2F87243EECDC2B5D7632E943C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_61C1740721D4ED1D5962B5D7632E21B2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_08572DF2F87243EECDC2B5D7632E943C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_42AE7FB3B10329BB8857B5D7632E7A9B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_08572DF2F87243EECDC2B5D7632E943C" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_42AE7FB3B10329BB8857B5D7632E7A9B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_338431A1D747D648D8A8B5D7632E1164" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_08572DF2F87243EECDC2B5D7632E943C" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_338431A1D747D648D8A8B5D7632E1164" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_9E85ADDA2BC8185DADAAB5D7632E8C32" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_08572DF2F87243EECDC2B5D7632E943C" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_9E85ADDA2BC8185DADAAB5D7632E8C32" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_2A01EAF76DC40B828DB3B5D7632E0EBC" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_61C1740721D4ED1D5962B5D7632E21B2" xlink:to="loc_us-gaap_Depreciation_2A01EAF76DC40B828DB3B5D7632E0EBC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireProductiveAssets" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_2BCB568D017AC8A7D737B5D7632EBA18" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_61C1740721D4ED1D5962B5D7632E21B2" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_2BCB568D017AC8A7D737B5D7632EBA18" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/PropertyAndEquipmentnetTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAbstract_87FE40754104D8F673C5BBEB9B07D5BC" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTextBlock_652674CA4B6059B52043BBEB9B078120" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentAbstract_87FE40754104D8F673C5BBEB9B07D5BC" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTextBlock_652674CA4B6059B52043BBEB9B078120" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/RelatedPartyTransactions" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="loc_us-gaap_RelatedPartyTransactionsAbstract_7ADD4A7D7C3A0908EC6CBBEB9C5F57D7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionsDisclosureTextBlock" xlink:label="loc_us-gaap_RelatedPartyTransactionsDisclosureTextBlock_76B6C23B109C478FBDBDBBEB9C5F5C49" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RelatedPartyTransactionsAbstract_7ADD4A7D7C3A0908EC6CBBEB9C5F57D7" xlink:to="loc_us-gaap_RelatedPartyTransactionsDisclosureTextBlock_76B6C23B109C478FBDBDBBEB9C5F5C49" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/RelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionsAbstract" xlink:label="loc_us-gaap_RelatedPartyTransactionsAbstract_FD7F997B915394310B5AB5D75FD5E781" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_3B917552B277F74B4EE6B5D75FD5D87C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RelatedPartyTransactionsAbstract_FD7F997B915394310B5AB5D75FD5E781" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_3B917552B277F74B4EE6B5D75FD5D87C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherCommitmentsAxis" xlink:label="loc_us-gaap_OtherCommitmentsAxis_277B5785FD3B46D3C9BEB5D75FD5676D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_3B917552B277F74B4EE6B5D75FD5D87C" xlink:to="loc_us-gaap_OtherCommitmentsAxis_277B5785FD3B46D3C9BEB5D75FD5676D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherCommitmentsDomain" xlink:label="loc_us-gaap_OtherCommitmentsDomain_D5EFCD230B9330EDA2B1B5D75FD5469E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsAxis_277B5785FD3B46D3C9BEB5D75FD5676D" xlink:to="loc_us-gaap_OtherCommitmentsDomain_D5EFCD230B9330EDA2B1B5D75FD5469E" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ContingencyFeeArrangementMember" xlink:label="loc_ftnt_ContingencyFeeArrangementMember_ADB46ACA75BF3639D6C6B5D75FD5F497" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherCommitmentsDomain_D5EFCD230B9330EDA2B1B5D75FD5469E" xlink:to="loc_ftnt_ContingencyFeeArrangementMember_ADB46ACA75BF3639D6C6B5D75FD5F497" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_718D9BCB2049F7DF13B4B5D75FD568A7" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_3B917552B277F74B4EE6B5D75FD5D87C" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_718D9BCB2049F7DF13B4B5D75FD568A7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:label="loc_us-gaap_RelatedPartyDomain_221B18106B913773DA5CB5D75FD574A5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_718D9BCB2049F7DF13B4B5D75FD568A7" xlink:to="loc_us-gaap_RelatedPartyDomain_221B18106B913773DA5CB5D75FD574A5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ImmediateFamilyMemberOfManagementOrPrincipalOwnerMember" xlink:label="loc_us-gaap_ImmediateFamilyMemberOfManagementOrPrincipalOwnerMember_9A74C39FE580608A7C4EB5D75FD5C2B1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RelatedPartyDomain_221B18106B913773DA5CB5D75FD574A5" xlink:to="loc_us-gaap_ImmediateFamilyMemberOfManagementOrPrincipalOwnerMember_9A74C39FE580608A7C4EB5D75FD5C2B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_EF132B38BA701DC214E0B5D75FD50222" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_3B917552B277F74B4EE6B5D75FD5D87C" xlink:to="loc_us-gaap_RelatedPartyTransactionLineItems_EF132B38BA701DC214E0B5D75FD50222" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_032F2D68B992A9161FC6B5D75FD58F14" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_EF132B38BA701DC214E0B5D75FD50222" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_032F2D68B992A9161FC6B5D75FD58F14" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsPayableRelatedPartiesCurrentAndNoncurrent" xlink:label="loc_us-gaap_AccountsPayableRelatedPartiesCurrentAndNoncurrent_7E635C850AB35F629D27B5D75FD5820A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_EF132B38BA701DC214E0B5D75FD50222" xlink:to="loc_us-gaap_AccountsPayableRelatedPartiesCurrentAndNoncurrent_7E635C850AB35F629D27B5D75FD5820A" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/RestructuringCharges" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringAndRelatedActivitiesAbstract" xlink:label="loc_us-gaap_RestructuringAndRelatedActivitiesAbstract_57A043E046D4DC6B0753BBEB9C8474FA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringAndRelatedActivitiesDisclosureTextBlock" xlink:label="loc_us-gaap_RestructuringAndRelatedActivitiesDisclosureTextBlock_CCB027F80F9F1748FDDCBBEB9C84A0D5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringAndRelatedActivitiesAbstract_57A043E046D4DC6B0753BBEB9C8474FA" xlink:to="loc_us-gaap_RestructuringAndRelatedActivitiesDisclosureTextBlock_CCB027F80F9F1748FDDCBBEB9C84A0D5" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/RestructuringChargesAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringAndRelatedActivitiesAbstract" xlink:label="loc_us-gaap_RestructuringAndRelatedActivitiesAbstract_AF67307ACEA0B6F454F9B9809BD82EEC" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_45D879B99189CAFC4739B9809BD89FD2" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringAndRelatedActivitiesAbstract_AF67307ACEA0B6F454F9B9809BD82EEC" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_45D879B99189CAFC4739B9809BD89FD2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringPlanAxis" xlink:label="loc_us-gaap_RestructuringPlanAxis_17C3A12D77E82DAB6876B9809BD8A076" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_45D879B99189CAFC4739B9809BD89FD2" xlink:to="loc_us-gaap_RestructuringPlanAxis_17C3A12D77E82DAB6876B9809BD8A076" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringPlanDomain" xlink:label="loc_us-gaap_RestructuringPlanDomain_CB74B1DC2B8FF2CCCEF7B9809BD8A78D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringPlanAxis_17C3A12D77E82DAB6876B9809BD8A076" xlink:to="loc_us-gaap_RestructuringPlanDomain_CB74B1DC2B8FF2CCCEF7B9809BD8A78D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_9848BB204137FD0840D0B9809BD950FF" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_45D879B99189CAFC4739B9809BD89FD2" xlink:to="loc_us-gaap_RestructuringCostAndReserveLineItems_9848BB204137FD0840D0B9809BD950FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_A4CA3DEC156B6C236258B9809BD96E82" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_9848BB204137FD0840D0B9809BD950FF" xlink:to="loc_us-gaap_RestructuringCharges_A4CA3DEC156B6C236258B9809BD96E82" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringReserve" xlink:label="loc_us-gaap_RestructuringReserve_90A699F19ACB132C1847B9809BD9F99B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_9848BB204137FD0840D0B9809BD950FF" xlink:to="loc_us-gaap_RestructuringReserve_90A699F19ACB132C1847B9809BD9F99B" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/RestructuringChargesRestructuringActivityDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringAndRelatedActivitiesAbstract" xlink:label="loc_us-gaap_RestructuringAndRelatedActivitiesAbstract_658B93A8C4F30276EA7CB14829DBC11F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_60C22C72C9E72773974AB14829DBBD1F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringAndRelatedActivitiesAbstract_658B93A8C4F30276EA7CB14829DBC11F" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_60C22C72C9E72773974AB14829DBBD1F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_0268DF642A806D0A04C1B14829DB2956" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_60C22C72C9E72773974AB14829DBBD1F" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_0268DF642A806D0A04C1B14829DB2956" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_04E432B36729C3F7F850B14829DBD00E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_0268DF642A806D0A04C1B14829DB2956" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_04E432B36729C3F7F850B14829DBD00E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeSeveranceMember" xlink:label="loc_us-gaap_EmployeeSeveranceMember_9E69DEC28E76D129BEFBB14829DBF536" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_04E432B36729C3F7F850B14829DBD00E" xlink:to="loc_us-gaap_EmployeeSeveranceMember_9E69DEC28E76D129BEFBB14829DBF536" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ContractTerminationMember" xlink:label="loc_us-gaap_ContractTerminationMember_01AF4458C1777D9A4213B14829DB3BB3" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_04E432B36729C3F7F850B14829DBD00E" xlink:to="loc_us-gaap_ContractTerminationMember_01AF4458C1777D9A4213B14829DB3BB3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_090181139D2CA865C88CB14829DB2759" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_60C22C72C9E72773974AB14829DBBD1F" xlink:to="loc_us-gaap_RestructuringCostAndReserveLineItems_090181139D2CA865C88CB14829DB2759" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringReserve" xlink:label="loc_us-gaap_RestructuringReserve_0DBD2706BC854960AD15B14829DBF284" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_090181139D2CA865C88CB14829DB2759" xlink:to="loc_us-gaap_RestructuringReserve_0DBD2706BC854960AD15B14829DBF284" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_8CD2B79760C21062AE34B14829DB649E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_090181139D2CA865C88CB14829DB2759" xlink:to="loc_us-gaap_RestructuringCharges_8CD2B79760C21062AE34B14829DB649E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsForRestructuring" xlink:label="loc_us-gaap_PaymentsForRestructuring_6B44FA7CC23315C7A4FCB14829DB117D" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_090181139D2CA865C88CB14829DB2759" xlink:to="loc_us-gaap_PaymentsForRestructuring_6B44FA7CC23315C7A4FCB14829DB117D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringReserveSettledWithoutCash2" xlink:label="loc_us-gaap_RestructuringReserveSettledWithoutCash2_C90DEDEB257A4E948518B14829DB7044" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_090181139D2CA865C88CB14829DB2759" xlink:to="loc_us-gaap_RestructuringReserveSettledWithoutCash2_C90DEDEB257A4E948518B14829DB7044" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringReserve" xlink:label="loc_us-gaap_RestructuringReserve_B6CBBCAE8F9C4C09FE25B14829DBB61C" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_090181139D2CA865C88CB14829DB2759" xlink:to="loc_us-gaap_RestructuringReserve_B6CBBCAE8F9C4C09FE25B14829DBB61C" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/RestructuringChargesTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringAndRelatedActivitiesAbstract" xlink:label="loc_us-gaap_RestructuringAndRelatedActivitiesAbstract_FD98B8AFE607A56AA06ABBEB9CC05FE3" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_1A0159CF3D8CA6F1807DBBEB9CC099E5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RestructuringAndRelatedActivitiesAbstract_FD98B8AFE607A56AA06ABBEB9CC05FE3" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock_1A0159CF3D8CA6F1807DBBEB9CC099E5" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/ScheduleIiValuationAndQualifyingAccounts" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsAbstract" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsAbstract_9588DC6017D4489F4EB7BBEB9C87925E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock" xlink:label="loc_us-gaap_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_5445CFE452B944893608BBEB9C8700E5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsAbstract_9588DC6017D4489F4EB7BBEB9C87925E" xlink:to="loc_us-gaap_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock_5445CFE452B944893608BBEB9C8700E5" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/ScheduleIiValuationAndQualifyingAccountsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsAbstract" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsAbstract_5ABDDD7F50A0F5A38029BBEB9BD4705D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsDisclosureTable" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_633AD40E384ACF75826DBBEB9BD41020" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsAbstract_5ABDDD7F50A0F5A38029BBEB9BD4705D" xlink:to="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_633AD40E384ACF75826DBBEB9BD41020" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_EEFB0A0A48918462B1B6BBEB9BD4A4F6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_633AD40E384ACF75826DBBEB9BD41020" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_EEFB0A0A48918462B1B6BBEB9BD4A4F6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_21A7D926AC7ED032ACA0BBEB9BD481E8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_EEFB0A0A48918462B1B6BBEB9BD4A4F6" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_21A7D926AC7ED032ACA0BBEB9BD481E8" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AllowanceforDoubtfulAccountsReserveforSalesReturnsMember" xlink:label="loc_ftnt_AllowanceforDoubtfulAccountsReserveforSalesReturnsMember_C8A2255704748D700771BBEB9BD4FB11" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_21A7D926AC7ED032ACA0BBEB9BD481E8" xlink:to="loc_ftnt_AllowanceforDoubtfulAccountsReserveforSalesReturnsMember_C8A2255704748D700771BBEB9BD4FB11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_00605A1AEFA1C7DA6F2ABBEB9BD4668A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_633AD40E384ACF75826DBBEB9BD41020" xlink:to="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_00605A1AEFA1C7DA6F2ABBEB9BD4668A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35D3D074D8D88518274FBBEB9BD41CD6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_00605A1AEFA1C7DA6F2ABBEB9BD4668A" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35D3D074D8D88518274FBBEB9BD41CD6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_A2898280A4507D7A833ABBEB9BD40C16" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35D3D074D8D88518274FBBEB9BD41CD6" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_A2898280A4507D7A833ABBEB9BD40C16" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_EE5EE60812BC6CFAB8F5BBEB9BD488FA" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35D3D074D8D88518274FBBEB9BD41CD6" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_EE5EE60812BC6CFAB8F5BBEB9BD488FA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_A1954CB6FCE0A137CD74BBEB9BD4DA51" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_35D3D074D8D88518274FBBEB9BD41CD6" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_A1954CB6FCE0A137CD74BBEB9BD4DA51" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SegmentInformation" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:label="loc_us-gaap_SegmentReportingAbstract_BB38C1BB95D5469E1B3BBBEB9C0A9002" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="loc_us-gaap_SegmentReportingDisclosureTextBlock_47FFB0073FB6D9C8D0B7BBEB9C0AA8F7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingAbstract_BB38C1BB95D5469E1B3BBBEB9C0A9002" xlink:to="loc_us-gaap_SegmentReportingDisclosureTextBlock_47FFB0073FB6D9C8D0B7BBEB9C0AA8F7" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SegmentInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:label="loc_us-gaap_SegmentReportingAbstract_79A3A50DAF8F617D4030BB2692745435" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_C604B44035E001CFFEDABB269274BB7A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingAbstract_79A3A50DAF8F617D4030BB2692745435" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_C604B44035E001CFFEDABB269274BB7A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementGeographicalAxis" xlink:label="loc_us-gaap_StatementGeographicalAxis_02E90B937C2DE341A7E4BB26927A402E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_C604B44035E001CFFEDABB269274BB7A" xlink:to="loc_us-gaap_StatementGeographicalAxis_02E90B937C2DE341A7E4BB26927A402E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="loc_us-gaap_SegmentGeographicalDomain_7D0186F2D56706133856BB26927AE488" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementGeographicalAxis_02E90B937C2DE341A7E4BB26927A402E" xlink:to="loc_us-gaap_SegmentGeographicalDomain_7D0186F2D56706133856BB26927AE488" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmericasMember" xlink:label="loc_us-gaap_AmericasMember_81140A5C6059F4138004BB26927AA3DC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentGeographicalDomain_7D0186F2D56706133856BB26927AE488" xlink:to="loc_us-gaap_AmericasMember_81140A5C6059F4138004BB26927AA3DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_07C5888ADF2519E737B6BB26927A5C32" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AmericasMember_81140A5C6059F4138004BB26927AA3DC" xlink:to="loc_country_US_07C5888ADF2519E737B6BB26927A5C32" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_CA" xlink:label="loc_country_CA_222D21F70236DEF071F0BB26927AB5BB" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AmericasMember_81140A5C6059F4138004BB26927AA3DC" xlink:to="loc_country_CA_222D21F70236DEF071F0BB26927AB5BB" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_OtherAmericasMember" xlink:label="loc_ftnt_OtherAmericasMember_3388CA1070600DBE57EABB26927AF07D" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AmericasMember_81140A5C6059F4138004BB26927AA3DC" xlink:to="loc_ftnt_OtherAmericasMember_3388CA1070600DBE57EABB26927AF07D" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EuropeMiddleEastAndAfricaMember" xlink:label="loc_ftnt_EuropeMiddleEastAndAfricaMember_FDB36BB650129BB096AABB26927A4B45" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentGeographicalDomain_7D0186F2D56706133856BB26927AE488" xlink:to="loc_ftnt_EuropeMiddleEastAndAfricaMember_FDB36BB650129BB096AABB26927A4B45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_FR" xlink:label="loc_country_FR_1E8DFF6AF52F61A77B10BB26927A7186" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_EuropeMiddleEastAndAfricaMember_FDB36BB650129BB096AABB26927A4B45" xlink:to="loc_country_FR_1E8DFF6AF52F61A77B10BB26927A7186" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_OtherEuropeMiddleEastandAfricanCountriesMember" xlink:label="loc_ftnt_OtherEuropeMiddleEastandAfricanCountriesMember_3A0897E84D516E288371BB26927BB028" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_EuropeMiddleEastAndAfricaMember_FDB36BB650129BB096AABB26927A4B45" xlink:to="loc_ftnt_OtherEuropeMiddleEastandAfricanCountriesMember_3A0897E84D516E288371BB26927BB028" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_AsiaPacificAndJapanMember" xlink:label="loc_ftnt_AsiaPacificAndJapanMember_251C996440C430FD42EEBB26927BF1B0" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentGeographicalDomain_7D0186F2D56706133856BB26927AE488" xlink:to="loc_ftnt_AsiaPacificAndJapanMember_251C996440C430FD42EEBB26927BF1B0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_AllCountriesDomain" xlink:label="loc_country_AllCountriesDomain_68CCEC13BDDFEE92ECA2BB26929E75FE" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentGeographicalDomain_7D0186F2D56706133856BB26927AE488" xlink:to="loc_country_AllCountriesDomain_68CCEC13BDDFEE92ECA2BB26929E75FE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_1FCE341265B3B1AE98BFBB26927B4EC3" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_C604B44035E001CFFEDABB269274BB7A" xlink:to="loc_us-gaap_SegmentReportingInformationLineItems_1FCE341265B3B1AE98BFBB26927B4EC3" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_NumberOfBusinessActivities" xlink:label="loc_ftnt_NumberOfBusinessActivities_5D965DE00B2763AD0DF9BB26927B3873" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1FCE341265B3B1AE98BFBB26927B4EC3" xlink:to="loc_ftnt_NumberOfBusinessActivities_5D965DE00B2763AD0DF9BB26927B3873" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_NumberOfSegmentManagersResponsibleForOperations" xlink:label="loc_ftnt_NumberOfSegmentManagersResponsibleForOperations_8E8CCEC63DDC1C696F31BB26927BBD17" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1FCE341265B3B1AE98BFBB26927B4EC3" xlink:to="loc_ftnt_NumberOfSegmentManagersResponsibleForOperations_8E8CCEC63DDC1C696F31BB26927BBD17" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfOperatingSegments" xlink:label="loc_us-gaap_NumberOfOperatingSegments_F61C47C15099ECA686A6BB26927B7C16" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1FCE341265B3B1AE98BFBB26927B4EC3" xlink:to="loc_us-gaap_NumberOfOperatingSegments_F61C47C15099ECA686A6BB26927B7C16" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="loc_us-gaap_NumberOfReportableSegments_45DE9E9B82BCC2899D10BB26927BBB67" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1FCE341265B3B1AE98BFBB26927B4EC3" xlink:to="loc_us-gaap_NumberOfReportableSegments_45DE9E9B82BCC2899D10BB26927BBB67" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_34E7FDDB4CB30695573ABB26927B3665" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1FCE341265B3B1AE98BFBB26927B4EC3" xlink:to="loc_us-gaap_SalesRevenueNet_34E7FDDB4CB30695573ABB26927B3665" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_A7E73479D62CA8FCBA29BB26927B5D2C" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1FCE341265B3B1AE98BFBB26927B4EC3" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_A7E73479D62CA8FCBA29BB26927B5D2C" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SegmentInformationTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:label="loc_us-gaap_SegmentReportingAbstract_E39BD92D15B3C7C9B244BBEB9C8555E8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueFromExternalCustomersByGeographicAreasTableTextBlock" xlink:label="loc_us-gaap_RevenueFromExternalCustomersByGeographicAreasTableTextBlock_F62575CEE30F579EB46CBBEB9C858A11" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingAbstract_E39BD92D15B3C7C9B244BBEB9C8555E8" xlink:to="loc_us-gaap_RevenueFromExternalCustomersByGeographicAreasTableTextBlock_F62575CEE30F579EB46CBBEB9C858A11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongLivedAssetsByGeographicAreasTableTextBlock" xlink:label="loc_us-gaap_LongLivedAssetsByGeographicAreasTableTextBlock_D43B89012CDEF862712FBBEB9C85358B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingAbstract_E39BD92D15B3C7C9B244BBEB9C8555E8" xlink:to="loc_us-gaap_LongLivedAssetsByGeographicAreasTableTextBlock_D43B89012CDEF862712FBBEB9C85358B" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquity" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_58BCD072095C126A5CECBBEB9CB6A609" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_5DE43C8B6C568111F106BBEB9CB6C3DC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_58BCD072095C126A5CECBBEB9CB6A609" xlink:to="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_5DE43C8B6C568111F106BBEB9CB6C3DC" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityAdditionalInformationRelatedToEsppDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_A163E566AE6A49BE4D37BBEB9C332AA8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E114A3BC72628B73AA9FBBEB9C335DDF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_A163E566AE6A49BE4D37BBEB9C332AA8" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E114A3BC72628B73AA9FBBEB9C335DDF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_E83E7BB83EFFE5EB18ACBBEB9C330AA0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E114A3BC72628B73AA9FBBEB9C335DDF" xlink:to="loc_us-gaap_AwardTypeAxis_E83E7BB83EFFE5EB18ACBBEB9C330AA0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7F30DEB6491AA9DF938ABBEB9C33ECED" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_E83E7BB83EFFE5EB18ACBBEB9C330AA0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7F30DEB6491AA9DF938ABBEB9C33ECED" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EmployeeStockPurchasePlanMember" xlink:label="loc_ftnt_EmployeeStockPurchasePlanMember_51669425916FBF6CB678BBEB9C33BE97" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7F30DEB6491AA9DF938ABBEB9C33ECED" xlink:to="loc_ftnt_EmployeeStockPurchasePlanMember_51669425916FBF6CB678BBEB9C33BE97" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AB62B3808C8B85118E7CBBEB9C34537C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E114A3BC72628B73AA9FBBEB9C335DDF" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AB62B3808C8B85118E7CBBEB9C34537C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_CE0EF7F0AA1B5445AE0BBBEB9C34A639" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AB62B3808C8B85118E7CBBEB9C34537C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_CE0EF7F0AA1B5445AE0BBBEB9C34A639" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_426E5788120A547E4021BBEB9C347E29" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AB62B3808C8B85118E7CBBEB9C34537C" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_426E5788120A547E4021BBEB9C347E29" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsIssuedWeightedAveragePricePerShare" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsIssuedWeightedAveragePricePerShare_1B73828F2F6EBF53AE92BBEB9C34DC39" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AB62B3808C8B85118E7CBBEB9C34537C" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsIssuedWeightedAveragePricePerShare_1B73828F2F6EBF53AE92BBEB9C34DC39" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityAllocationOfStockBasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_4A5FA72E7B47E62C943EC7B14E26766D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_DA5917B3981ADD914CC8C7B14E262E8B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_4A5FA72E7B47E62C943EC7B14E26766D" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_DA5917B3981ADD914CC8C7B14E262E8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_7EA5F66CF9866543B98CC7B14E262A0A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_DA5917B3981ADD914CC8C7B14E262E8B" xlink:to="loc_us-gaap_AwardTypeAxis_7EA5F66CF9866543B98CC7B14E262A0A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_850FEE9DB2B3673740B5C7B14E2647F4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_7EA5F66CF9866543B98CC7B14E262A0A" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_850FEE9DB2B3673740B5C7B14E2647F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_EFE3FC718600E230ED91C7B14E26BA82" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_850FEE9DB2B3673740B5C7B14E2647F4" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_EFE3FC718600E230ED91C7B14E26BA82" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_24335828025A3F55C17BC7B14E26ABAA" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_850FEE9DB2B3673740B5C7B14E2647F4" xlink:to="loc_us-gaap_EmployeeStockOptionMember_24335828025A3F55C17BC7B14E26ABAA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeStockMember" xlink:label="loc_us-gaap_EmployeeStockMember_61AE1A60F731840DE885C7B14E269EF0" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_850FEE9DB2B3673740B5C7B14E2647F4" xlink:to="loc_us-gaap_EmployeeStockMember_61AE1A60F731840DE885C7B14E269EF0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_A4C9EA35DC8A81C19104C7B14E2631A1" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_DA5917B3981ADD914CC8C7B14E262E8B" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_A4C9EA35DC8A81C19104C7B14E2631A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_5B914BF58BCFD4C523C3C7B14E26776D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_A4C9EA35DC8A81C19104C7B14E2631A1" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_5B914BF58BCFD4C523C3C7B14E26776D" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_CostOfGoodsSoldMember" xlink:label="loc_ftnt_CostOfGoodsSoldMember_2A4BBE7D4E6FDB8FA1DBC7B14E263FB3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_5B914BF58BCFD4C523C3C7B14E26776D" xlink:to="loc_ftnt_CostOfGoodsSoldMember_2A4BBE7D4E6FDB8FA1DBC7B14E263FB3" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_CostOfServicesMember" xlink:label="loc_ftnt_CostOfServicesMember_BEDCB7C37D6A1645AF9AC7B14E2688BA" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_5B914BF58BCFD4C523C3C7B14E26776D" xlink:to="loc_ftnt_CostOfServicesMember_BEDCB7C37D6A1645AF9AC7B14E2688BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_377C2076F68D05CF84C3C7B14E26D528" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_5B914BF58BCFD4C523C3C7B14E26776D" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_377C2076F68D05CF84C3C7B14E26D528" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SellingAndMarketingExpenseMember" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_B972B03E7A916B2763B8C7B14E2608D4" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_5B914BF58BCFD4C523C3C7B14E26776D" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_B972B03E7A916B2763B8C7B14E2608D4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_EA0101A00DD64C603DD4C7B14E26ED4C" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_5B914BF58BCFD4C523C3C7B14E26776D" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_EA0101A00DD64C603DD4C7B14E26ED4C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_90985732913F7C702A8BC7B14E26F9D8" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_DA5917B3981ADD914CC8C7B14E262E8B" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_90985732913F7C702A8BC7B14E26F9D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_01D2D2D41DCEFB81158AC7B14E26B8FC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_90985732913F7C702A8BC7B14E26F9D8" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_01D2D2D41DCEFB81158AC7B14E26B8FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions_B3A083642B56BA780EDCC7BD4842AE75" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_90985732913F7C702A8BC7B14E26F9D8" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions_B3A083642B56BA780EDCC7BD4842AE75" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_673F4644C1EFC2661484B5D761925AB1" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_673F4644C1EFC2661484B5D761925AB1" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareRepurchaseProgramAxis" xlink:label="loc_us-gaap_ShareRepurchaseProgramAxis_1A18930D4A63A9A2E6DAB5D76193412B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:to="loc_us-gaap_ShareRepurchaseProgramAxis_1A18930D4A63A9A2E6DAB5D76193412B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareRepurchaseProgramDomain" xlink:label="loc_us-gaap_ShareRepurchaseProgramDomain_7EE2456B1E3F7E6B0A3FB5D76193363F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareRepurchaseProgramAxis_1A18930D4A63A9A2E6DAB5D76193412B" xlink:to="loc_us-gaap_ShareRepurchaseProgramDomain_7EE2456B1E3F7E6B0A3FB5D76193363F" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareRepurchaseProgramMember" xlink:label="loc_ftnt_ShareRepurchaseProgramMember_8C3A7812EA15F80A383BB5D76193A951" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareRepurchaseProgramDomain_7EE2456B1E3F7E6B0A3FB5D76193363F" xlink:to="loc_ftnt_ShareRepurchaseProgramMember_8C3A7812EA15F80A383BB5D76193A951" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_025E43AE9A1BE4C25429B5D761946C11" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_025E43AE9A1BE4C25429B5D761946C11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9C6FC5CE6C2984BF700CB5D7619460F0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_025E43AE9A1BE4C25429B5D761946C11" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9C6FC5CE6C2984BF700CB5D7619460F0" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_MeruNetworksInc.Member" xlink:label="loc_ftnt_MeruNetworksInc.Member_A3F4A22872549F276E65B5D76194B2A8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9C6FC5CE6C2984BF700CB5D7619460F0" xlink:to="loc_ftnt_MeruNetworksInc.Member_A3F4A22872549F276E65B5D76194B2A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_474E5C0F4887CDCC51AAB5D76194EA85" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:to="loc_us-gaap_RangeAxis_474E5C0F4887CDCC51AAB5D76194EA85" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_6F6E319A341D3C548429B5D76194F021" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeAxis_474E5C0F4887CDCC51AAB5D76194EA85" xlink:to="loc_us-gaap_RangeMember_6F6E319A341D3C548429B5D76194F021" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_2447448EEB45C6CC72F2B5D761949EAD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_6F6E319A341D3C548429B5D76194F021" xlink:to="loc_us-gaap_MinimumMember_2447448EEB45C6CC72F2B5D761949EAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_0401DE4505638FF0C8A1B5D761948A03" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_6F6E319A341D3C548429B5D76194F021" xlink:to="loc_us-gaap_MaximumMember_0401DE4505638FF0C8A1B5D761948A03" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesAxis" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesAxis_DA21FF92196A5F4001DDB5D76194FFC9" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesAxis_DA21FF92196A5F4001DDB5D76194FFC9" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesDomain" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesDomain_7D47B797B64309592E6DB5D76195351C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesAxis_DA21FF92196A5F4001DDB5D76194FFC9" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesDomain_7D47B797B64309592E6DB5D76195351C" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationAwardAuthorizedNumberChangesLesserOfFixedAmountOfSharesMember" xlink:label="loc_ftnt_ShareBasedCompensationAwardAuthorizedNumberChangesLesserOfFixedAmountOfSharesMember_6195AFD2CA9529944F32B5D76195189A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesDomain_7D47B797B64309592E6DB5D76195351C" xlink:to="loc_ftnt_ShareBasedCompensationAwardAuthorizedNumberChangesLesserOfFixedAmountOfSharesMember_6195AFD2CA9529944F32B5D76195189A" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationAwardAuthorizedNumberChangesLesserOfOutstandingSharesOnLastDayOfPreceedingYearMember" xlink:label="loc_ftnt_ShareBasedCompensationAwardAuthorizedNumberChangesLesserOfOutstandingSharesOnLastDayOfPreceedingYearMember_05D3BEB0A42315A66E8BB5D7619554D5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedSharesChangesDomain_7D47B797B64309592E6DB5D76195351C" xlink:to="loc_ftnt_ShareBasedCompensationAwardAuthorizedNumberChangesLesserOfOutstandingSharesOnLastDayOfPreceedingYearMember_05D3BEB0A42315A66E8BB5D7619554D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_8B67863D7A5D208E9B24B5D761952E47" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:to="loc_us-gaap_TitleOfIndividualAxis_8B67863D7A5D208E9B24B5D761952E47" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_63DE2E05A6F177289C47B5D761955BFF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualAxis_8B67863D7A5D208E9B24B5D761952E47" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_63DE2E05A6F177289C47B5D761955BFF" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_IndividualOwning10PercentOrMoreOfStockMember" xlink:label="loc_ftnt_IndividualOwning10PercentOrMoreOfStockMember_C9F3677C83130083EDC7B5D7619A92FE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_63DE2E05A6F177289C47B5D761955BFF" xlink:to="loc_ftnt_IndividualOwning10PercentOrMoreOfStockMember_C9F3677C83130083EDC7B5D7619A92FE" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EmployeeMember" xlink:label="loc_ftnt_EmployeeMember_CDF5AC1EF8D42EF35A73B5D7619BC35D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_63DE2E05A6F177289C47B5D761955BFF" xlink:to="loc_ftnt_EmployeeMember_CDF5AC1EF8D42EF35A73B5D7619BC35D" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_DirectorsAndOtherServiceProvidersMember" xlink:label="loc_ftnt_DirectorsAndOtherServiceProvidersMember_2DE04E0D7D7271FAF00BB5D7619B370C" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_63DE2E05A6F177289C47B5D761955BFF" xlink:to="loc_ftnt_DirectorsAndOtherServiceProvidersMember_2DE04E0D7D7271FAF00BB5D7619B370C" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_IndividualOwning10PercentOrLessOfStockMember" xlink:label="loc_ftnt_IndividualOwning10PercentOrLessOfStockMember_5B07574CE750AF4FAA3BB5D7619B9D0F" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_63DE2E05A6F177289C47B5D761955BFF" xlink:to="loc_ftnt_IndividualOwning10PercentOrLessOfStockMember_5B07574CE750AF4FAA3BB5D7619B9D0F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_F9432B80EBD882DE50B8B5D7619BEE6E" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:to="loc_us-gaap_PlanNameAxis_F9432B80EBD882DE50B8B5D7619BEE6E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_9CFA54803402F17713BFB5D7619BC154" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PlanNameAxis_F9432B80EBD882DE50B8B5D7619BEE6E" xlink:to="loc_us-gaap_PlanNameDomain_9CFA54803402F17713BFB5D7619BC154" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_StockPlans2000and2008Member" xlink:label="loc_ftnt_StockPlans2000and2008Member_854675F31DD97ADEBDC1B5D7619BCF65" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PlanNameDomain_9CFA54803402F17713BFB5D7619BC154" xlink:to="loc_ftnt_StockPlans2000and2008Member_854675F31DD97ADEBDC1B5D7619BCF65" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_StockPlan2009Member" xlink:label="loc_ftnt_StockPlan2009Member_7B234B4CFB5C93326752B5D7619B4DD3" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PlanNameDomain_9CFA54803402F17713BFB5D7619BC154" xlink:to="loc_ftnt_StockPlan2009Member_7B234B4CFB5C93326752B5D7619B4DD3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_BD5193A4FBD7080D8ECBB5D7619CA3B1" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:to="loc_us-gaap_AwardTypeAxis_BD5193A4FBD7080D8ECBB5D7619CA3B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_BD5193A4FBD7080D8ECBB5D7619CA3B1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_StockOptionsNonqualifyingMember" xlink:label="loc_ftnt_StockOptionsNonqualifyingMember_8A037C2BD61717B839E2B5D7619C5A19" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:to="loc_ftnt_StockOptionsNonqualifyingMember_8A037C2BD61717B839E2B5D7619C5A19" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_E480A42BA6CFCD5CE9D6B5D7619C79EB" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:to="loc_us-gaap_EmployeeStockOptionMember_E480A42BA6CFCD5CE9D6B5D7619C79EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeStockMember" xlink:label="loc_us-gaap_EmployeeStockMember_4B1F1D968DD00C955F22B5D7619CB58D" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:to="loc_us-gaap_EmployeeStockMember_4B1F1D968DD00C955F22B5D7619CB58D" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_StockOptionsAndRestrictedStockUnitsOutstandingMember" xlink:label="loc_ftnt_StockOptionsAndRestrictedStockUnitsOutstandingMember_6CF014FEBD4F5D9E4F50B5D7619C035D" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:to="loc_ftnt_StockOptionsAndRestrictedStockUnitsOutstandingMember_6CF014FEBD4F5D9E4F50B5D7619C035D" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ReservedForFutureOptionRestrictedStockUnitAndOtherEquityAwardGrantsMember" xlink:label="loc_ftnt_ReservedForFutureOptionRestrictedStockUnitAndOtherEquityAwardGrantsMember_59FCE90CC41609E0A311B5D7619C46E5" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:to="loc_ftnt_ReservedForFutureOptionRestrictedStockUnitAndOtherEquityAwardGrantsMember_59FCE90CC41609E0A311B5D7619C46E5" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ReservedForFutureEsppIssuancesMember" xlink:label="loc_ftnt_ReservedForFutureEsppIssuancesMember_B52DD6F483E305EBD7EDB5D7619C5E6D" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:to="loc_ftnt_ReservedForFutureEsppIssuancesMember_B52DD6F483E305EBD7EDB5D7619C5E6D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockCompensationPlanMember" xlink:label="loc_us-gaap_StockCompensationPlanMember_72B0DF58DE00C5DE402EB5D7619C0575" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_873C9D0948D3A16CBE78B5D7619CEC43" xlink:to="loc_us-gaap_StockCompensationPlanMember_72B0DF58DE00C5DE402EB5D7619C0575" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F9A374796DD14E115567B5D76192ECAE" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_D097F515856DFCBD5412B5D7619D7EA0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_D097F515856DFCBD5412B5D7619D7EA0" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumStockOwnershipPercentTriggeringEarlyAwardExpiration" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumStockOwnershipPercentTriggeringEarlyAwardExpiration_08C2801258000EC277D6B5D7619DC5D2" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumStockOwnershipPercentTriggeringEarlyAwardExpiration_08C2801258000EC277D6B5D7619DC5D2" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumExericsePriceAsPercentOfFairValueOnGrantDate" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumExericsePriceAsPercentOfFairValueOnGrantDate_AB75541658264D913D83B5D7619D91F3" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumExericsePriceAsPercentOfFairValueOnGrantDate_AB75541658264D913D83B5D7619D91F3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_76860A5139F1168C5DBBB5D7619DFCF4" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_76860A5139F1168C5DBBB5D7619DFCF4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_1F8B7A06D2E4FE6218E7B5D7619DF337" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_1F8B7A06D2E4FE6218E7B5D7619DF337" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_5064286AC8F0CA656ED5B5D7619DF611" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_5064286AC8F0CA656ED5B5D7619DF611" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedBeforeAdjustments" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedBeforeAdjustments_6FF5043BAFB84A8BC05EB5D7619DDBDD" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedBeforeAdjustments_6FF5043BAFB84A8BC05EB5D7619DDBDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_E3CA782CB31E5389866CB5D7619DC416" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_E3CA782CB31E5389866CB5D7619DC416" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncreaseToNumberOfSharesAuthorizedPerOriginalPlanTermsMaximum" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncreaseToNumberOfSharesAuthorizedPerOriginalPlanTermsMaximum_0DEE31AF21D08E76FEECB5D7619DCCD7" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncreaseToNumberOfSharesAuthorizedPerOriginalPlanTermsMaximum_0DEE31AF21D08E76FEECB5D7619DCCD7" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncreaseToNumberOfSharesAuthorizedPerOriginalPlanTermsMaximumPercent" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncreaseToNumberOfSharesAuthorizedPerOriginalPlanTermsMaximumPercent_80C3C19A88A3F7199173B5D7619DF683" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncreaseToNumberOfSharesAuthorizedPerOriginalPlanTermsMaximumPercent_80C3C19A88A3F7199173B5D7619DF683" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirationPeriod" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirationPeriod_830A52CDF44357C5BF45B5D7619D2B25" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardExpirationPeriod_830A52CDF44357C5BF45B5D7619D2B25" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumStockOwnershipPercentForOptionsGrantedToIndividuals" xlink:label="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumStockOwnershipPercentForOptionsGrantedToIndividuals_E37F2BB650B9DEE2533BB5D7619E58C6" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumStockOwnershipPercentForOptionsGrantedToIndividuals_E37F2BB650B9DEE2533BB5D7619E58C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:label="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_509E8D99DA9227AD3DE9B5D7619E006F" xlink:type="locator" />
    <link:presentationArc order="13" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_509E8D99DA9227AD3DE9B5D7619E006F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_40EFDD0C7FFA7F3210EBB5D7619E096A" xlink:type="locator" />
    <link:presentationArc order="14" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_40EFDD0C7FFA7F3210EBB5D7619E096A" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_PurchasePriceOfCommonStockAsPercentageOfLowerOfFairMarketValueOfCommonStockOnFirstDayOfOfferingPeriodOrLastDayOfPurchasePeriod" xlink:label="loc_ftnt_PurchasePriceOfCommonStockAsPercentageOfLowerOfFairMarketValueOfCommonStockOnFirstDayOfOfferingPeriodOrLastDayOfPurchasePeriod_2C838FC3F09E29AE10A8B5D7619ECE08" xlink:type="locator" />
    <link:presentationArc order="15" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_PurchasePriceOfCommonStockAsPercentageOfLowerOfFairMarketValueOfCommonStockOnFirstDayOfOfferingPeriodOrLastDayOfPurchasePeriod_2C838FC3F09E29AE10A8B5D7619ECE08" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EmployeeStockPurchasePlanPeriodicPurchaseLimit" xlink:label="loc_ftnt_EmployeeStockPurchasePlanPeriodicPurchaseLimit_BB0733411F8E920D11CCB5D7619E141C" xlink:type="locator" />
    <link:presentationArc order="16" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_EmployeeStockPurchasePlanPeriodicPurchaseLimit_BB0733411F8E920D11CCB5D7619E141C" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EmployeeStockPurchasePlanAnnualPurchaseLimit" xlink:label="loc_ftnt_EmployeeStockPurchasePlanAnnualPurchaseLimit_60185A552201A156163FB5D7619E545B" xlink:type="locator" />
    <link:presentationArc order="17" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_EmployeeStockPurchasePlanAnnualPurchaseLimit_60185A552201A156163FB5D7619E545B" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_BusinessCombinationNonOptionEquityInstrumentAssumedFairValue" xlink:label="loc_ftnt_BusinessCombinationNonOptionEquityInstrumentAssumedFairValue_AC510DB791A8CB7DB2B2B5D7619E966D" xlink:type="locator" />
    <link:presentationArc order="18" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_BusinessCombinationNonOptionEquityInstrumentAssumedFairValue_AC510DB791A8CB7DB2B2B5D7619E966D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_B4D5F2EA18ACF3BD52FAB5D7619EB49B" xlink:type="locator" />
    <link:presentationArc order="19" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_B4D5F2EA18ACF3BD52FAB5D7619EB49B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_B17EC92AE197DCC07EC2B5D7619E8F08" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_B4D5F2EA18ACF3BD52FAB5D7619EB49B" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_B17EC92AE197DCC07EC2B5D7619E8F08" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_CC40B58E62951CD96940B5D7619E3B2D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_B4D5F2EA18ACF3BD52FAB5D7619EB49B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_CC40B58E62951CD96940B5D7619E3B2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_29336F29A8DACAD803EFB5D7619E8E0A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_B4D5F2EA18ACF3BD52FAB5D7619EB49B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_29336F29A8DACAD803EFB5D7619E8E0A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_7CD4D7659C3E65694A1EB5D7619ECCF0" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsAndMethodologyAbstract_B4D5F2EA18ACF3BD52FAB5D7619EB49B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_7CD4D7659C3E65694A1EB5D7619ECCF0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_C36189ED18FEB96B73E5B5D7619ECBAB" xlink:type="locator" />
    <link:presentationArc order="20" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_C36189ED18FEB96B73E5B5D7619ECBAB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_7F42B5E2A73AC70CC0C3B5D7619F9A06" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_C36189ED18FEB96B73E5B5D7619ECBAB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_7F42B5E2A73AC70CC0C3B5D7619F9A06" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_E82C143376CB8DC636A4B5D761A4CFF0" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_C36189ED18FEB96B73E5B5D7619ECBAB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_E82C143376CB8DC636A4B5D761A4CFF0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_FB8E6D847FB19E011BA5B5D761A4E788" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_C36189ED18FEB96B73E5B5D7619ECBAB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_FB8E6D847FB19E011BA5B5D761A4E788" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_508BCEA9B5223D27BE73B5D761A4B8B3" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_C36189ED18FEB96B73E5B5D7619ECBAB" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_508BCEA9B5223D27BE73B5D761A4B8B3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_76F134AE562F0B86F3F8B5D761A42873" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_C36189ED18FEB96B73E5B5D7619ECBAB" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_76F134AE562F0B86F3F8B5D761A42873" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_51B5556700C576CEEE89B5D761A4F3BD" xlink:type="locator" />
    <link:presentationArc order="21" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_51B5556700C576CEEE89B5D761A4F3BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_7FD2B166E7C7A47035E4B5D761A4B877" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_51B5556700C576CEEE89B5D761A4F3BD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_7FD2B166E7C7A47035E4B5D761A4B877" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_F2FA3F93782431899CA3B5D761A49FBD" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_51B5556700C576CEEE89B5D761A4F3BD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_F2FA3F93782431899CA3B5D761A49FBD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_3D74B9FB9010B3625C9CB5D761A42F3C" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_51B5556700C576CEEE89B5D761A4F3BD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_3D74B9FB9010B3625C9CB5D761A42F3C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_F49E912ABAE90D5215B7B5D761A5ED1F" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_51B5556700C576CEEE89B5D761A4F3BD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_F49E912ABAE90D5215B7B5D761A5ED1F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_A4611049AC0A17F17337B5D761A52CDB" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_51B5556700C576CEEE89B5D761A4F3BD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_A4611049AC0A17F17337B5D761A52CDB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:type="locator" />
    <link:presentationArc order="22" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_1B8F03F96F201831723DB5D761A5509E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_1B8F03F96F201831723DB5D761A5509E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice_1E740C31B78819DF4092B5D761A543ED" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice_1E740C31B78819DF4092B5D761A543ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1_B2E8F26D680B043D979DB5D761A510DF" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1_B2E8F26D680B043D979DB5D761A510DF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_057F79CA525CD6AE0788B5D761A5B1E2" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_057F79CA525CD6AE0788B5D761A5B1E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_6F0C654C043C2928B230B5D761A5E78C" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_6F0C654C043C2928B230B5D761A5E78C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_D185A15EFC3E46F04FF3B5D761A5A61F" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_D185A15EFC3E46F04FF3B5D761A5A61F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_C8F2ACB0DA86D168CA8EB5D761A54360" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_C8F2ACB0DA86D168CA8EB5D761A54360" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_37BAB05157F200D993FEB5D761A690DA" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_69691F4DC73F745D3553B5D761A51F7C" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_37BAB05157F200D993FEB5D761A690DA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_C11CE850815D5691CB93B5D761A6EF2E" xlink:type="locator" />
    <link:presentationArc order="23" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_C11CE850815D5691CB93B5D761A6EF2E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_01A8E49FC4C0FFB71188B5D761A69469" xlink:type="locator" />
    <link:presentationArc order="24" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_01A8E49FC4C0FFB71188B5D761A69469" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_82F6EF6F1BC1ECEBE231B5D761A648D9" xlink:type="locator" />
    <link:presentationArc order="25" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_82F6EF6F1BC1ECEBE231B5D761A648D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_DCF7EC8209C9293BC464B5D761A6C01F" xlink:type="locator" />
    <link:presentationArc order="26" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_DCF7EC8209C9293BC464B5D761A6C01F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_31D76AAEAD855B13A082B5D761A66801" xlink:type="locator" />
    <link:presentationArc order="27" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_31D76AAEAD855B13A082B5D761A66801" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_BusinessCombinationConsiderationTransferredFairValueEarnedEquityAwardsAssumed" xlink:label="loc_ftnt_BusinessCombinationConsiderationTransferredFairValueEarnedEquityAwardsAssumed_F79845A923C245FAA050B5D761A63397" xlink:type="locator" />
    <link:presentationArc order="28" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_ftnt_BusinessCombinationConsiderationTransferredFairValueEarnedEquityAwardsAssumed_F79845A923C245FAA050B5D761A63397" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_9D08E71BA4EFAAC3A528B5D761A6A127" xlink:type="locator" />
    <link:presentationArc order="29" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AD3BBAE871BC6BE415ACB5D7619DB2FD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_9D08E71BA4EFAAC3A528B5D761A6A127" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityEsppInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_67542D1D5D2796889C79BBEB9C01B3B3" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4AEFF3A94B2C214D2DA9BBEB9C01C352" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_67542D1D5D2796889C79BBEB9C01B3B3" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4AEFF3A94B2C214D2DA9BBEB9C01C352" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_000949C63917FF767004BBEB9C015FEF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4AEFF3A94B2C214D2DA9BBEB9C01C352" xlink:to="loc_us-gaap_AwardTypeAxis_000949C63917FF767004BBEB9C015FEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_EA50B1C7D4081AD23D78BBEB9C01CA98" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_000949C63917FF767004BBEB9C015FEF" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_EA50B1C7D4081AD23D78BBEB9C01CA98" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EmployeeStockPurchasePlanMember" xlink:label="loc_ftnt_EmployeeStockPurchasePlanMember_9EFB8926528633641AE8BBEB9C0108CE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_EA50B1C7D4081AD23D78BBEB9C01CA98" xlink:to="loc_ftnt_EmployeeStockPurchasePlanMember_9EFB8926528633641AE8BBEB9C0108CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_07B3788F77CD5D791272BBEB9C019E8B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4AEFF3A94B2C214D2DA9BBEB9C01C352" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_07B3788F77CD5D791272BBEB9C019E8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_19CC380EA4F8BBDB6AECBBEB9C0155F9" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_07B3788F77CD5D791272BBEB9C019E8B" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_19CC380EA4F8BBDB6AECBBEB9C0155F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_21CBA13853B211AC009EBBEB9C01D13F" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_07B3788F77CD5D791272BBEB9C019E8B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_21CBA13853B211AC009EBBEB9C01D13F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_D6387E6BC8DF295D5AD6BBEB9C01ECFF" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_07B3788F77CD5D791272BBEB9C019E8B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_D6387E6BC8DF295D5AD6BBEB9C01ECFF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_374B617418F4ED5A7A51BBEB9C012A4B" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_07B3788F77CD5D791272BBEB9C019E8B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_374B617418F4ED5A7A51BBEB9C012A4B" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityPerformanceStockUnitsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_CD6E13F3F4F254DE709DB9809B9EEBB7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7D27E589A2973162499AB9809B9E6757" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_CD6E13F3F4F254DE709DB9809B9EEBB7" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7D27E589A2973162499AB9809B9E6757" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_793502B9D5CFF2616953B9809B9E9BA4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7D27E589A2973162499AB9809B9E6757" xlink:to="loc_us-gaap_TitleOfIndividualAxis_793502B9D5CFF2616953B9809B9E9BA4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_29A0B35BB36999189F3DB9809B9E0314" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualAxis_793502B9D5CFF2616953B9809B9E9BA4" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_29A0B35BB36999189F3DB9809B9E0314" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EmployeeMember" xlink:label="loc_ftnt_EmployeeMember_8CC27AB280B3C129B43CB9809B9F1BA4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_29A0B35BB36999189F3DB9809B9E0314" xlink:to="loc_ftnt_EmployeeMember_8CC27AB280B3C129B43CB9809B9F1BA4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VestingAxis" xlink:label="loc_us-gaap_VestingAxis_71867D3A847ED0722291B9809B9F6E3A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7D27E589A2973162499AB9809B9E6757" xlink:to="loc_us-gaap_VestingAxis_71867D3A847ED0722291B9809B9F6E3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VestingDomain" xlink:label="loc_us-gaap_VestingDomain_F0B5A30B34B3A2FBE2E4B9809B9F2ED8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_VestingAxis_71867D3A847ED0722291B9809B9F6E3A" xlink:to="loc_us-gaap_VestingDomain_F0B5A30B34B3A2FBE2E4B9809B9F2ED8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_F3CE28F565A3AC4C8A65B9809B9F7DC5" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7D27E589A2973162499AB9809B9E6757" xlink:to="loc_us-gaap_AwardTypeAxis_F3CE28F565A3AC4C8A65B9809B9F7DC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_93F52A42DA01E52DD9E7B9809B9F2DEB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_F3CE28F565A3AC4C8A65B9809B9F7DC5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_93F52A42DA01E52DD9E7B9809B9F2DEB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_72F6E854B1E987CD40B6B9809B9FBAB5" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7D27E589A2973162499AB9809B9E6757" xlink:to="loc_us-gaap_RangeAxis_72F6E854B1E987CD40B6B9809B9FBAB5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_4C069A06576FDE78BC9FB9809B9FD1DC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeAxis_72F6E854B1E987CD40B6B9809B9FBAB5" xlink:to="loc_us-gaap_RangeMember_4C069A06576FDE78BC9FB9809B9FD1DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_DA2FBA94732B072B1169B9809B9FDAFA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_4C069A06576FDE78BC9FB9809B9FD1DC" xlink:to="loc_us-gaap_MinimumMember_DA2FBA94732B072B1169B9809B9FDAFA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_F831FA29E8DE5DD4F4A3B9809B9F29C8" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_4C069A06576FDE78BC9FB9809B9FD1DC" xlink:to="loc_us-gaap_MaximumMember_F831FA29E8DE5DD4F4A3B9809B9F29C8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C93E61E5C7564EAD06B1B9809B9F474F" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7D27E589A2973162499AB9809B9E6757" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C93E61E5C7564EAD06B1B9809B9F474F" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_PerformanceShareWeightedAverageAssumptionsAbstract" xlink:label="loc_ftnt_PerformanceShareWeightedAverageAssumptionsAbstract_FC88669D9DBDBCD16B9FB9809B9F9EB8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C93E61E5C7564EAD06B1B9809B9F474F" xlink:to="loc_ftnt_PerformanceShareWeightedAverageAssumptionsAbstract_FC88669D9DBDBCD16B9FB9809B9F9EB8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_A2DFACD65AA3C46C5E47B9809B9F7B35" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_PerformanceShareWeightedAverageAssumptionsAbstract_FC88669D9DBDBCD16B9FB9809B9F9EB8" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_A2DFACD65AA3C46C5E47B9809B9F7B35" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_B4DA8253DEE3DDC3F808B9809BA07705" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_PerformanceShareWeightedAverageAssumptionsAbstract_FC88669D9DBDBCD16B9FB9809B9F9EB8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_B4DA8253DEE3DDC3F808B9809BA07705" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_1C55F3064F823F9DBE02B9809BA09ADE" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_PerformanceShareWeightedAverageAssumptionsAbstract_FC88669D9DBDBCD16B9FB9809B9F9EB8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_1C55F3064F823F9DBE02B9809BA09ADE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_67FE72D98336055DBFCEB9809BA013E5" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_PerformanceShareWeightedAverageAssumptionsAbstract_FC88669D9DBDBCD16B9FB9809B9F9EB8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_67FE72D98336055DBFCEB9809BA013E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_A39BE9FDE187B1CD2474B9809BA0BC85" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C93E61E5C7564EAD06B1B9809B9F474F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_A39BE9FDE187B1CD2474B9809BA0BC85" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_231B666E2CF6ADEADA70B9809BA0BCA2" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C93E61E5C7564EAD06B1B9809B9F474F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_231B666E2CF6ADEADA70B9809BA0BCA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_C845EFC870656859F943B9809BA0A235" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C93E61E5C7564EAD06B1B9809B9F474F" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_C845EFC870656859F943B9809BA0A235" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_D428B69675E79F44420CB9809BA0FFBF" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_C93E61E5C7564EAD06B1B9809B9F474F" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_D428B69675E79F44420CB9809BA0FFBF" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityRangeOfOptionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_F4E9EFE6989DE89BFAA2B9809BA4FD72" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_81A78B3B6BC8DCBE27BDB9809BA4F2C7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_F4E9EFE6989DE89BFAA2B9809BA4FD72" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_81A78B3B6BC8DCBE27BDB9809BA4F2C7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_0141E1CAC3C94FF36DC3B9809BA48D4C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_81A78B3B6BC8DCBE27BDB9809BA4F2C7" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_0141E1CAC3C94FF36DC3B9809BA48D4C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_5ACF176EFCAC5B30A609B9809BA44CF6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_0141E1CAC3C94FF36DC3B9809BA48D4C" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_5ACF176EFCAC5B30A609B9809BA44CF6" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_Range843To899Member" xlink:label="loc_ftnt_Range843To899Member_F371DC6055E16C31EA6AB9809BA44E3B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_5ACF176EFCAC5B30A609B9809BA44CF6" xlink:to="loc_ftnt_Range843To899Member_F371DC6055E16C31EA6AB9809BA44E3B" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_Range15.28to19.94Member" xlink:label="loc_ftnt_Range15.28to19.94Member_D259047DAE268CB0EA97B9809BA4ABC2" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_5ACF176EFCAC5B30A609B9809BA44CF6" xlink:to="loc_ftnt_Range15.28to19.94Member_D259047DAE268CB0EA97B9809BA4ABC2" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_Range2013To2396Member" xlink:label="loc_ftnt_Range2013To2396Member_EC9698C48B5978A6B05EB9809BA43D54" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_5ACF176EFCAC5B30A609B9809BA44CF6" xlink:to="loc_ftnt_Range2013To2396Member_EC9698C48B5978A6B05EB9809BA43D54" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_Range26.49to26.70Member" xlink:label="loc_ftnt_Range26.49to26.70Member_53BC560E71D347E2A5F4B9809BA43D8E" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_5ACF176EFCAC5B30A609B9809BA44CF6" xlink:to="loc_ftnt_Range26.49to26.70Member_53BC560E71D347E2A5F4B9809BA43D8E" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_Range31.39to33.31Member" xlink:label="loc_ftnt_Range31.39to33.31Member_5BA6D383024AB0E3297FB9809BA44239" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_5ACF176EFCAC5B30A609B9809BA44CF6" xlink:to="loc_ftnt_Range31.39to33.31Member_5BA6D383024AB0E3297FB9809BA44239" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_81A78B3B6BC8DCBE27BDB9809BA4F2C7" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_5632CBEA888BBCE4A836B9809BA5FDBD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_5632CBEA888BBCE4A836B9809BA5FDBD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_7EA13D3EE8723F8702F2B9809BA5A524" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_7EA13D3EE8723F8702F2B9809BA5A524" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_4A19262AF599F52FF584B9809BA5D475" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_4A19262AF599F52FF584B9809BA5D475" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_473F9B23088750F8EEE7B9809BA55E3A" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_473F9B23088750F8EEE7B9809BA55E3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1_13077076A1A303610F67B9809BA5D0DB" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1_13077076A1A303610F67B9809BA5D0DB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_0A2761CC865BE811DEE9B9809BA523D8" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_0A2761CC865BE811DEE9B9809BA523D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_6085D4BF46782B47393CB9809BA597A3" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_5F9F1AC8A15899DEA8E0B9809BA5832C" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_6085D4BF46782B47393CB9809BA597A3" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityRestrictedStockUnitsActivityDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_0BD969184C45ECF56455BBEB9C3A268A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_22DC32741712CFB390FCBBEB9C3A8285" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_0BD969184C45ECF56455BBEB9C3A268A" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_22DC32741712CFB390FCBBEB9C3A8285" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_361FBA7E1F73BDCD590FBBEB9C3AE1D4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_22DC32741712CFB390FCBBEB9C3A8285" xlink:to="loc_us-gaap_AwardTypeAxis_361FBA7E1F73BDCD590FBBEB9C3AE1D4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AD3B98472836B63E50C1BBEB9C3A4869" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_361FBA7E1F73BDCD590FBBEB9C3AE1D4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AD3B98472836B63E50C1BBEB9C3A4869" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_377485C11E975F66D489BBEB9C3A6808" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AD3B98472836B63E50C1BBEB9C3A4869" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_377485C11E975F66D489BBEB9C3A6808" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D10D2A46849BCC3C8160BBEB9C3AAD80" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_22DC32741712CFB390FCBBEB9C3A8285" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D10D2A46849BCC3C8160BBEB9C3AAD80" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6E2CDAB80E793051C239BBEB9C3BDA63" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D10D2A46849BCC3C8160BBEB9C3AAD80" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6E2CDAB80E793051C239BBEB9C3BDA63" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_0C523422D6A0D20B25FBBBEB9C3B659A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6E2CDAB80E793051C239BBEB9C3BDA63" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_0C523422D6A0D20B25FBBBEB9C3B659A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_92F0104917A9D18D4152BBEB9C3B98FF" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6E2CDAB80E793051C239BBEB9C3BDA63" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_92F0104917A9D18D4152BBEB9C3B98FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_B895362DB69B0801AA81BBEB9C3BC4FE" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6E2CDAB80E793051C239BBEB9C3BDA63" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_B895362DB69B0801AA81BBEB9C3BC4FE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_EE6A3E5A86E766CCAEC3BBEB9C3B56B9" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6E2CDAB80E793051C239BBEB9C3BDA63" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_EE6A3E5A86E766CCAEC3BBEB9C3B56B9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_F42694101A0A8703F274BBEB9C3B3B71" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_6E2CDAB80E793051C239BBEB9C3BDA63" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_F42694101A0A8703F274BBEB9C3B3B71" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_E0A9985CAD5B12477E0FBBEB9C3B273B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D10D2A46849BCC3C8160BBEB9C3AAD80" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_E0A9985CAD5B12477E0FBBEB9C3B273B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_BE38F82049268658280ABBEB9C3BA3EB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_E0A9985CAD5B12477E0FBBEB9C3B273B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_BE38F82049268658280ABBEB9C3BA3EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_6536F313777A22035B32BBEB9C3BA725" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_E0A9985CAD5B12477E0FBBEB9C3B273B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_6536F313777A22035B32BBEB9C3BA725" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_C6535F29FE2243E38E3ABBEB9C3B2BBC" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_E0A9985CAD5B12477E0FBBEB9C3B273B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_C6535F29FE2243E38E3ABBEB9C3B2BBC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_BE7ABFCD61B6132A853BBBEB9C3B3985" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_E0A9985CAD5B12477E0FBBEB9C3B273B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_BE7ABFCD61B6132A853BBBEB9C3B3985" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_716050C09C3EF8F90D7DBBEB9C3BE72A" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_E0A9985CAD5B12477E0FBBEB9C3B273B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_716050C09C3EF8F90D7DBBEB9C3BE72A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_E186CF6E1381E8E3ABA6BBEB9C3BFB20" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D10D2A46849BCC3C8160BBEB9C3AAD80" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_E186CF6E1381E8E3ABA6BBEB9C3BFB20" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_4FA818EFC6B675470678BBEB9C3B71D7" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D10D2A46849BCC3C8160BBEB9C3AAD80" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_4FA818EFC6B675470678BBEB9C3B71D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_9EC0CA3C429BD6A27779BBEB9C3B0B7D" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D10D2A46849BCC3C8160BBEB9C3AAD80" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_9EC0CA3C429BD6A27779BBEB9C3B0B7D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_93AD5F9D4AEFE1D227F6BBEB9C3B0ABD" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D10D2A46849BCC3C8160BBEB9C3AAD80" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_93AD5F9D4AEFE1D227F6BBEB9C3B0ABD" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityShareRepurchaseProgramDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_450CF31BAA6C544F4C80B5D760B81F82" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_111869980F9B39DCDC26B5D760B84D71" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_450CF31BAA6C544F4C80B5D760B81F82" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_111869980F9B39DCDC26B5D760B84D71" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareRepurchaseProgramAxis" xlink:label="loc_us-gaap_ShareRepurchaseProgramAxis_6C2182B97E97C50D3DB6B5D760B87CBC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_111869980F9B39DCDC26B5D760B84D71" xlink:to="loc_us-gaap_ShareRepurchaseProgramAxis_6C2182B97E97C50D3DB6B5D760B87CBC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareRepurchaseProgramDomain" xlink:label="loc_us-gaap_ShareRepurchaseProgramDomain_1EC3263A3419FC216B65B5D760B9613E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareRepurchaseProgramAxis_6C2182B97E97C50D3DB6B5D760B87CBC" xlink:to="loc_us-gaap_ShareRepurchaseProgramDomain_1EC3263A3419FC216B65B5D760B9613E" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ShareRepurchaseProgramMember" xlink:label="loc_ftnt_ShareRepurchaseProgramMember_5E6CC6DAFE9F7825F539B5D760B94755" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareRepurchaseProgramDomain_1EC3263A3419FC216B65B5D760B9613E" xlink:to="loc_ftnt_ShareRepurchaseProgramMember_5E6CC6DAFE9F7825F539B5D760B94755" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_61CB23D478548517AE15B5D760B973BC" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_111869980F9B39DCDC26B5D760B84D71" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_61CB23D478548517AE15B5D760B973BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_CDEB70DE5DE41115D2AEB5D760B994A3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_61CB23D478548517AE15B5D760B973BC" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_CDEB70DE5DE41115D2AEB5D760B994A3" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_StockRepurchaseProgramAdditionalAuthorizedAmount" xlink:label="loc_ftnt_StockRepurchaseProgramAdditionalAuthorizedAmount_1FEF1F993DB3E976F542B5D760BF885E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_61CB23D478548517AE15B5D760B973BC" xlink:to="loc_ftnt_StockRepurchaseProgramAdditionalAuthorizedAmount_1FEF1F993DB3E976F542B5D760BF885E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_F2CDC3EDE52EF4D0FD2EB5D760BF67A4" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_61CB23D478548517AE15B5D760B973BC" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_F2CDC3EDE52EF4D0FD2EB5D760BF67A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_401DC0B7F84C1DE9144CB5D760BFB282" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_61CB23D478548517AE15B5D760B973BC" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_401DC0B7F84C1DE9144CB5D760BFB282" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_6CFA64B3574846DDAA8CB5D760BF145B" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_61CB23D478548517AE15B5D760B973BC" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_6CFA64B3574846DDAA8CB5D760BF145B" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/StockholdersEquityTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_C95F638747D003701EBDBBEB9C29E465" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock_C95F638747D003701EBDBBEB9C29E465" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleofSharebasedCompensationSharesWithheldforTaxesTableTextBlock" xlink:label="loc_ftnt_ScheduleofSharebasedCompensationSharesWithheldforTaxesTableTextBlock_11306481485066ACD1C4BBEB9C292C85" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_ftnt_ScheduleofSharebasedCompensationSharesWithheldforTaxesTableTextBlock_11306481485066ACD1C4BBEB9C292C85" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsAndAllocationOfRecognizedPeriodCostsTableTextBlock" xlink:label="loc_ftnt_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsAndAllocationOfRecognizedPeriodCostsTableTextBlock_8B5FF5AD08AB6EC45ED1BBEB9C29B541" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_ftnt_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsAndAllocationOfRecognizedPeriodCostsTableTextBlock_8B5FF5AD08AB6EC45ED1BBEB9C29B541" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_32204B1CFC636DB29D23BBEB9C29C726" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_32204B1CFC636DB29D23BBEB9C29C726" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleofSharebasedCompensationStockOptionsActivityAdditionalInformationTableTextBlock" xlink:label="loc_ftnt_ScheduleofSharebasedCompensationStockOptionsActivityAdditionalInformationTableTextBlock_E8FDF7BA60697320D0EBBBEB9C296524" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_ftnt_ScheduleofSharebasedCompensationStockOptionsActivityAdditionalInformationTableTextBlock_E8FDF7BA60697320D0EBBBEB9C296524" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock_E8293E69FFF297469183BBEB9C29C223" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock_E8293E69FFF297469183BBEB9C29C223" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock_AAE789B497214CE51D80BBEB9C29C4EF" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock_AAE789B497214CE51D80BBEB9C29C4EF" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanAdditionalInformationTableTextBlock" xlink:label="loc_ftnt_ScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanAdditionalInformationTableTextBlock_DB84BDB88B3EAFD1EB6FBBEB9C290AE8" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_ftnt_ScheduleofSharebasedPaymentAwardEmployeeStockPurchasePlanAdditionalInformationTableTextBlock_DB84BDB88B3EAFD1EB6FBBEB9C290AE8" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleOfSharesReservedForFutureIssuanceTableTextBlock" xlink:label="loc_ftnt_ScheduleOfSharesReservedForFutureIssuanceTableTextBlock_51A6060C727D9422104EBBEB9C29DEDB" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_ftnt_ScheduleOfSharesReservedForFutureIssuanceTableTextBlock_51A6060C727D9422104EBBEB9C29DEDB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_BC04CFE08548D384E38EBBEB9C29D759" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_BC04CFE08548D384E38EBBEB9C29D759" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleofEmployeeServiceSharebasedCompensationAllocationofRecognizedPeriodCostsbyAwardTypeTableTextBlock" xlink:label="loc_ftnt_ScheduleofEmployeeServiceSharebasedCompensationAllocationofRecognizedPeriodCostsbyAwardTypeTableTextBlock_DB07DD5F80A0DD0543B5BBEB9C2948DA" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_ftnt_ScheduleofEmployeeServiceSharebasedCompensationAllocationofRecognizedPeriodCostsbyAwardTypeTableTextBlock_DB07DD5F80A0DD0543B5BBEB9C2948DA" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_IncomeTaxBenefitFromStockOptionPlansTableTextBlock" xlink:label="loc_ftnt_IncomeTaxBenefitFromStockOptionPlansTableTextBlock_D874F9E560022212FE69BBEB9C2938DC" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9C62516E3D39A972E6DEBBEB9C295F7E" xlink:to="loc_ftnt_IncomeTaxBenefitFromStockOptionPlansTableTextBlock_D874F9E560022212FE69BBEB9C2938DC" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPolicies" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_BDB6333A20DCABF29AFBBBEB9C628AA6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="loc_us-gaap_SignificantAccountingPoliciesTextBlock_930FE859213B3EE3BAD8BBEB9C620D9B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_BDB6333A20DCABF29AFBBBEB9C628AA6" xlink:to="loc_us-gaap_SignificantAccountingPoliciesTextBlock_930FE859213B3EE3BAD8BBEB9C620D9B" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesAccountsReceivableDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_D1D51BB5A45526B22040B5D763E33883" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsDisclosureTable" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_5DD738D10C2D91D10906B5D763E32021" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_D1D51BB5A45526B22040B5D763E33883" xlink:to="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_5DD738D10C2D91D10906B5D763E32021" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_12DD3C914D2875217186B5D763E3B334" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_5DD738D10C2D91D10906B5D763E32021" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_12DD3C914D2875217186B5D763E3B334" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_316A23C1DE5A2AE400D8B5D763E31647" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_12DD3C914D2875217186B5D763E3B334" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_316A23C1DE5A2AE400D8B5D763E31647" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllowanceForSalesReturnsMember" xlink:label="loc_us-gaap_AllowanceForSalesReturnsMember_40375166B19545A5ADDEB5D763E395FC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_316A23C1DE5A2AE400D8B5D763E31647" xlink:to="loc_us-gaap_AllowanceForSalesReturnsMember_40375166B19545A5ADDEB5D763E395FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsMember" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsMember_7FF096EEC25DEB5A5201B5D763E3A33A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_316A23C1DE5A2AE400D8B5D763E31647" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsMember_7FF096EEC25DEB5A5201B5D763E3A33A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems" xlink:label="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_3ED2AE8B8876EF2203E1B5D763E3F7B7" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureTable_5DD738D10C2D91D10906B5D763E32021" xlink:to="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_3ED2AE8B8876EF2203E1B5D763E3F7B7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_188D35E990DF9D7709B1B5D763E4A785" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems_3ED2AE8B8876EF2203E1B5D763E3F7B7" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_188D35E990DF9D7709B1B5D763E4A785" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesCashCashEquivalentsAndAvailableForSaleInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_D4F9D17817F11B5667B2BBEB9CC29A82" xlink:type="locator" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_InvestmentsClassificationAsShortTermMinimumOriginalMaturity" xlink:label="loc_ftnt_InvestmentsClassificationAsShortTermMinimumOriginalMaturity_E7D547BA4F7BEA847AA5BBEB9CC2BDFC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_D4F9D17817F11B5667B2BBEB9CC29A82" xlink:to="loc_ftnt_InvestmentsClassificationAsShortTermMinimumOriginalMaturity_E7D547BA4F7BEA847AA5BBEB9CC2BDFC" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_InvestmentsClassificationAsShortTermMaximumOriginalMaturity" xlink:label="loc_ftnt_InvestmentsClassificationAsShortTermMaximumOriginalMaturity_EC5312BF42322F25744DBBEB9CC205C5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_D4F9D17817F11B5667B2BBEB9CC29A82" xlink:to="loc_ftnt_InvestmentsClassificationAsShortTermMaximumOriginalMaturity_EC5312BF42322F25744DBBEB9CC205C5" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_InvestmentsClassificationAsLongTermMinimumMaturity" xlink:label="loc_ftnt_InvestmentsClassificationAsLongTermMinimumMaturity_9F2FF362414BA3FF1426BBEB9CC25F96" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_D4F9D17817F11B5667B2BBEB9CC29A82" xlink:to="loc_ftnt_InvestmentsClassificationAsLongTermMinimumMaturity_9F2FF362414BA3FF1426BBEB9CC25F96" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesConcentrationOfCreditRiskDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_C461C4D5A78D60BF65C7B5D764085E31" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskTable" xlink:label="loc_us-gaap_ConcentrationRiskTable_8D1A9C6A0312DFF66879B5D76408B344" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C461C4D5A78D60BF65C7B5D764085E31" xlink:to="loc_us-gaap_ConcentrationRiskTable_8D1A9C6A0312DFF66879B5D76408B344" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_78C61B4E99FDDBA33EC0B5D76408A618" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskTable_8D1A9C6A0312DFF66879B5D76408B344" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_78C61B4E99FDDBA33EC0B5D76408A618" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_7DF06CC6CE80634F7B33B5D76408D32D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_78C61B4E99FDDBA33EC0B5D76408A618" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_7DF06CC6CE80634F7B33B5D76408D32D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_B7979E50D3E6BDCD867EB5D76408EC1D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_7DF06CC6CE80634F7B33B5D76408D32D" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_B7979E50D3E6BDCD867EB5D76408EC1D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MajorCustomersAxis" xlink:label="loc_us-gaap_MajorCustomersAxis_0B9F8749DB2A2CCC4A57B5D7640881C5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskTable_8D1A9C6A0312DFF66879B5D76408B344" xlink:to="loc_us-gaap_MajorCustomersAxis_0B9F8749DB2A2CCC4A57B5D7640881C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NameOfMajorCustomerDomain" xlink:label="loc_us-gaap_NameOfMajorCustomerDomain_10C2024CFBE3D476567DB5D764086751" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorCustomersAxis_0B9F8749DB2A2CCC4A57B5D7640881C5" xlink:to="loc_us-gaap_NameOfMajorCustomerDomain_10C2024CFBE3D476567DB5D764086751" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ExclusiveNetworksGroupMember" xlink:label="loc_ftnt_ExclusiveNetworksGroupMember_94C55F0844B20872C13FB5D76408687F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain_10C2024CFBE3D476567DB5D764086751" xlink:to="loc_ftnt_ExclusiveNetworksGroupMember_94C55F0844B20872C13FB5D76408687F" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_FinTecComputersMember" xlink:label="loc_ftnt_FinTecComputersMember_99C780AAC5A040D68213B5D76408B330" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NameOfMajorCustomerDomain_10C2024CFBE3D476567DB5D764086751" xlink:to="loc_ftnt_FinTecComputersMember_99C780AAC5A040D68213B5D76408B330" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_F6C177A3C9A4CBD6BF19B5D764084C99" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskTable_8D1A9C6A0312DFF66879B5D76408B344" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_F6C177A3C9A4CBD6BF19B5D764084C99" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_894FBA716CA18EE2FE3DB5D764092F9E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_F6C177A3C9A4CBD6BF19B5D764084C99" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_894FBA716CA18EE2FE3DB5D764092F9E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsReceivableMember" xlink:label="loc_us-gaap_AccountsReceivableMember_62C450B8C9B2C02AA551B5D7640969AC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_894FBA716CA18EE2FE3DB5D764092F9E" xlink:to="loc_us-gaap_AccountsReceivableMember_62C450B8C9B2C02AA551B5D7640969AC" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_SalesRevenueMember" xlink:label="loc_ftnt_SalesRevenueMember_F3FAAC84C13311D3CC6FB5D764094029" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_894FBA716CA18EE2FE3DB5D764092F9E" xlink:to="loc_ftnt_SalesRevenueMember_F3FAAC84C13311D3CC6FB5D764094029" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskLineItems" xlink:label="loc_us-gaap_ConcentrationRiskLineItems_A39B9452925C44C3819EB5D7640933B5" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskTable_8D1A9C6A0312DFF66879B5D76408B344" xlink:to="loc_us-gaap_ConcentrationRiskLineItems_A39B9452925C44C3819EB5D7640933B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_724143FA521E5E10A140B5D76409855F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConcentrationRiskLineItems_A39B9452925C44C3819EB5D7640933B5" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_724143FA521E5E10A140B5D76409855F" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesDerivativesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_FE6F15B110E01EAA0AD9B5D763CCEB5E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_C66A779EA6F062B2AC5AB5D763CCFAA2" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_FE6F15B110E01EAA0AD9B5D763CCEB5E" xlink:to="loc_us-gaap_DerivativeTable_C66A779EA6F062B2AC5AB5D763CCFAA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PositionAxis" xlink:label="loc_us-gaap_PositionAxis_EFEB063ED9F3F700EEC2B5D763D13115" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DerivativeTable_C66A779EA6F062B2AC5AB5D763CCFAA2" xlink:to="loc_us-gaap_PositionAxis_EFEB063ED9F3F700EEC2B5D763D13115" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PositionDomain" xlink:label="loc_us-gaap_PositionDomain_367732EED51DF075008AB5D763D1A1FF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PositionAxis_EFEB063ED9F3F700EEC2B5D763D13115" xlink:to="loc_us-gaap_PositionDomain_367732EED51DF075008AB5D763D1A1FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShortMember" xlink:label="loc_us-gaap_ShortMember_672F07AC1485288DBDEFB5D763D16621" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PositionDomain_367732EED51DF075008AB5D763D1A1FF" xlink:to="loc_us-gaap_ShortMember_672F07AC1485288DBDEFB5D763D16621" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrencyAxis" xlink:label="loc_us-gaap_CurrencyAxis_76F00A287E2B54978F80B5D763D2F09A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DerivativeTable_C66A779EA6F062B2AC5AB5D763CCFAA2" xlink:to="loc_us-gaap_CurrencyAxis_76F00A287E2B54978F80B5D763D2F09A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/currency/2017/currency-2017-01-31.xsd#currency_AllCurrenciesDomain" xlink:label="loc_currency_AllCurrenciesDomain_EF9AE96740F7CC38215BB5D763D276E3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CurrencyAxis_76F00A287E2B54978F80B5D763D2F09A" xlink:to="loc_currency_AllCurrenciesDomain_EF9AE96740F7CC38215BB5D763D276E3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/currency/2017/currency-2017-01-31.xsd#currency_CAD" xlink:label="loc_currency_CAD_E61E845D5B0A4E8D5EA9B5D763D2CFA6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_currency_AllCurrenciesDomain_EF9AE96740F7CC38215BB5D763D276E3" xlink:to="loc_currency_CAD_E61E845D5B0A4E8D5EA9B5D763D2CFA6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_79E5E710BA01A29E97B0B5D763D21769" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DerivativeTable_C66A779EA6F062B2AC5AB5D763CCFAA2" xlink:to="loc_us-gaap_DerivativeLineItems_79E5E710BA01A29E97B0B5D763D21769" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_795399B1D5CEAD59419DB5D763D252B0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DerivativeLineItems_79E5E710BA01A29E97B0B5D763D21769" xlink:to="loc_invest_DerivativeNotionalAmount_795399B1D5CEAD59419DB5D763D252B0" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesForeignCurrencyTranslationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_623CDDE81068706124A2BBEB9C8BB67F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_5D886BBC309CAA1C7691BBEB9C8BFE11" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_623CDDE81068706124A2BBEB9C8BB67F" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_5D886BBC309CAA1C7691BBEB9C8BFE11" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesGoodwillDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_E9B76E29F46452627FAABBEB9C2D9894" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfReportingUnits" xlink:label="loc_us-gaap_NumberOfReportingUnits_8E11A590BDB3BA160437BBEB9C2D5E8D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_E9B76E29F46452627FAABBEB9C2D9894" xlink:to="loc_us-gaap_NumberOfReportingUnits_8E11A590BDB3BA160437BBEB9C2D5E8D" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesOtherIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_0BE76B13A6B5C11B06D3BBEB9BB1487A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_28391526A0F0388113BABBEB9BB17A1E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_0BE76B13A6B5C11B06D3BBEB9BB1487A" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_28391526A0F0388113BABBEB9BB17A1E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_D0BC7589348ABF009CFEBBEB9BB10155" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_28391526A0F0388113BABBEB9BB17A1E" xlink:to="loc_us-gaap_RangeAxis_D0BC7589348ABF009CFEBBEB9BB10155" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_91583FB518940D2288E7BBEB9BB15DDB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeAxis_D0BC7589348ABF009CFEBBEB9BB10155" xlink:to="loc_us-gaap_RangeMember_91583FB518940D2288E7BBEB9BB15DDB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_B8D350F6EDEA2B1FBEA0BBEB9BB16861" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_91583FB518940D2288E7BBEB9BB15DDB" xlink:to="loc_us-gaap_MinimumMember_B8D350F6EDEA2B1FBEA0BBEB9BB16861" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_23C5021E5430D3B41854BBEB9BB18605" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_91583FB518940D2288E7BBEB9BB15DDB" xlink:to="loc_us-gaap_MaximumMember_23C5021E5430D3B41854BBEB9BB18605" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_841ECB661D9C945F61A0BBEB9BB19684" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_28391526A0F0388113BABBEB9BB17A1E" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_841ECB661D9C945F61A0BBEB9BB19684" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_A68E24B4A48FAD9AAB07BBEB9BB1ED25" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_841ECB661D9C945F61A0BBEB9BB19684" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_A68E24B4A48FAD9AAB07BBEB9BB1ED25" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesPolicies" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:type="locator" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_PresentationAndPreparationOfConsolidatedFinancialStatementsPolicyTextBlock" xlink:label="loc_ftnt_PresentationAndPreparationOfConsolidatedFinancialStatementsPolicyTextBlock_AFCC4A69898D573198BFB5D76412FBDD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_ftnt_PresentationAndPreparationOfConsolidatedFinancialStatementsPolicyTextBlock_AFCC4A69898D573198BFB5D76412FBDD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="loc_us-gaap_UseOfEstimates_7E2F0C4A68F58A201385B5D76412119D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_UseOfEstimates_7E2F0C4A68F58A201385B5D76412119D" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ConcentrationRiskPolicyTextBlock" xlink:label="loc_ftnt_ConcentrationRiskPolicyTextBlock_3A01D9C8A53E319555FFB5D76412AB00" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_ftnt_ConcentrationRiskPolicyTextBlock_3A01D9C8A53E319555FFB5D76412AB00" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueOfFinancialInstrumentsPolicy" xlink:label="loc_us-gaap_FairValueOfFinancialInstrumentsPolicy_6CC0BCD050F23FDCE17EB5D764125921" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_FairValueOfFinancialInstrumentsPolicy_6CC0BCD050F23FDCE17EB5D764125921" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ComprehensiveIncomeLossPolicyTextBlock" xlink:label="loc_ftnt_ComprehensiveIncomeLossPolicyTextBlock_5A78F5D06972D7A150D9B5D76412BB3D" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_ftnt_ComprehensiveIncomeLossPolicyTextBlock_5A78F5D06972D7A150D9B5D76412BB3D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" xlink:label="loc_us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_A079BD503DCA31837E64B5D764127530" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_A079BD503DCA31837E64B5D764127530" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_CashandCashEquivalentsandAvailableforSaleInvestmentsPolicyTextBlock" xlink:label="loc_ftnt_CashandCashEquivalentsandAvailableforSaleInvestmentsPolicyTextBlock_2EDC72F19280B2053576B5D764127B43" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_ftnt_CashandCashEquivalentsandAvailableforSaleInvestmentsPolicyTextBlock_2EDC72F19280B2053576B5D764127B43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryPolicyTextBlock" xlink:label="loc_us-gaap_InventoryPolicyTextBlock_08FD4586745611FDC985B5D76412032F" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_InventoryPolicyTextBlock_08FD4586745611FDC985B5D76412032F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_224592F62C9EFA6F8909B5D764125E2C" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_224592F62C9EFA6F8909B5D764125E2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostMethodInvestmentsPolicy" xlink:label="loc_us-gaap_CostMethodInvestmentsPolicy_37CB1076DDCDFAAA6996B5D764127F64" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_CostMethodInvestmentsPolicy_37CB1076DDCDFAAA6996B5D764127F64" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationVariableInterestEntityPolicy" xlink:label="loc_us-gaap_ConsolidationVariableInterestEntityPolicy_121A67CF513FA79D00C9B5D76412DF58" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_ConsolidationVariableInterestEntityPolicy_121A67CF513FA79D00C9B5D76412DF58" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationsPolicy" xlink:label="loc_us-gaap_BusinessCombinationsPolicy_6A3666F167D9BB138B53B5D764123E8E" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_BusinessCombinationsPolicy_6A3666F167D9BB138B53B5D764123E8E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock" xlink:label="loc_us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_7D6EC794B116CD16FF55B5D764120011" xlink:type="locator" />
    <link:presentationArc order="13" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_ImpairmentOrDisposalOfLongLivedAssetsPolicyTextBlock_7D6EC794B116CD16FF55B5D764120011" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyTextBlock" xlink:label="loc_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyTextBlock_A30DBC6CA7EC16B2C92CB5D764127499" xlink:type="locator" />
    <link:presentationArc order="14" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_CostsAssociatedWithExitOrDisposalActivitiesOrRestructuringsPolicyTextBlock_A30DBC6CA7EC16B2C92CB5D764127499" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_33267C2FFA90853D24D1B5D76412C9E5" xlink:type="locator" />
    <link:presentationArc order="15" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetsGoodwillPolicy_33267C2FFA90853D24D1B5D76412C9E5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsFiniteLivedPolicy" xlink:label="loc_us-gaap_IntangibleAssetsFiniteLivedPolicy_3431D4CD79CC40260BA9B5D764138B2D" xlink:type="locator" />
    <link:presentationArc order="16" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_IntangibleAssetsFiniteLivedPolicy_3431D4CD79CC40260BA9B5D764138B2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueRecognitionDeferredRevenue" xlink:label="loc_us-gaap_RevenueRecognitionDeferredRevenue_8EB5CCC72551537371E1B5D76412365E" xlink:type="locator" />
    <link:presentationArc order="17" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_RevenueRecognitionDeferredRevenue_8EB5CCC72551537371E1B5D76412365E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:label="loc_us-gaap_IncomeTaxPolicyTextBlock_D252867318B1F94084B7B5D764131815" xlink:type="locator" />
    <link:presentationArc order="18" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_IncomeTaxPolicyTextBlock_D252867318B1F94084B7B5D764131815" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:label="loc_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_5F35CC4F67F91C682C6BB5D764139213" xlink:type="locator" />
    <link:presentationArc order="19" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_5F35CC4F67F91C682C6BB5D764139213" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LesseeLeasesPolicyTextBlock" xlink:label="loc_us-gaap_LesseeLeasesPolicyTextBlock_71A8720F46102E25B3E0B5D76413F8BA" xlink:type="locator" />
    <link:presentationArc order="20" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_LesseeLeasesPolicyTextBlock_71A8720F46102E25B3E0B5D76413F8BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdvertisingCostPolicyExpensedAdvertisingCost" xlink:label="loc_us-gaap_AdvertisingCostPolicyExpensedAdvertisingCost_A671FAA94488B45C967AB5D76413C9D9" xlink:type="locator" />
    <link:presentationArc order="21" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_AdvertisingCostPolicyExpensedAdvertisingCost_A671FAA94488B45C967AB5D76413C9D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpensePolicy_890DDE8DFB6FBC8E60DAB5D764139D25" xlink:type="locator" />
    <link:presentationArc order="22" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpensePolicy_890DDE8DFB6FBC8E60DAB5D764139D25" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SoftwareToBeSoldLeasedOrOtherwiseMarketedPolicy" xlink:label="loc_us-gaap_SoftwareToBeSoldLeasedOrOtherwiseMarketedPolicy_2FA6CC934B68FA2394F6B5D764137F88" xlink:type="locator" />
    <link:presentationArc order="23" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_SoftwareToBeSoldLeasedOrOtherwiseMarketedPolicy_2FA6CC934B68FA2394F6B5D764137F88" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:label="loc_us-gaap_RevenueRecognitionPolicyTextBlock_B3B2F86C58D8D31C4D34B5D764133175" xlink:type="locator" />
    <link:presentationArc order="24" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_RevenueRecognitionPolicyTextBlock_B3B2F86C58D8D31C4D34B5D764133175" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShippingAndHandlingCostPolicyTextBlock" xlink:label="loc_us-gaap_ShippingAndHandlingCostPolicyTextBlock_CD57B924301C06C62806B5D764134062" xlink:type="locator" />
    <link:presentationArc order="25" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_ShippingAndHandlingCostPolicyTextBlock_CD57B924301C06C62806B5D764134062" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:label="loc_us-gaap_TradeAndOtherAccountsReceivablePolicy_A5C95D626F7E562B76B5B5D7641376FE" xlink:type="locator" />
    <link:presentationArc order="26" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_TradeAndOtherAccountsReceivablePolicy_A5C95D626F7E562B76B5B5D7641376FE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StandardProductWarrantyPolicy" xlink:label="loc_us-gaap_StandardProductWarrantyPolicy_4706BB9DF556622B7045B5D76413FF91" xlink:type="locator" />
    <link:presentationArc order="27" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_StandardProductWarrantyPolicy_4706BB9DF556622B7045B5D76413FF91" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativesMethodsOfAccountingHedgingDerivatives" xlink:label="loc_us-gaap_DerivativesMethodsOfAccountingHedgingDerivatives_D16B2F88B9ABF92B7A1DB5D76413DB60" xlink:type="locator" />
    <link:presentationArc order="28" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_DerivativesMethodsOfAccountingHedgingDerivatives_D16B2F88B9ABF92B7A1DB5D76413DB60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_48AC4E35B45706FFF8DAB5D7641327AF" xlink:type="locator" />
    <link:presentationArc order="29" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C812CC3A6A1A64A80372B5D7641198E3" xlink:to="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_48AC4E35B45706FFF8DAB5D7641327AF" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesPropertyAndEquipmentDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_667731936E5885886271BEE5A15186DB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_EC001DC078554F1B3700BEE5A152AF29" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_667731936E5885886271BEE5A15186DB" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_EC001DC078554F1B3700BEE5A152AF29" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_2373BE7AD38E6EEF2660BEE5A1521C58" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_EC001DC078554F1B3700BEE5A152AF29" xlink:to="loc_us-gaap_RangeAxis_2373BE7AD38E6EEF2660BEE5A1521C58" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_6C13FF0F83F3D0C7516BBEE5A152AFC0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeAxis_2373BE7AD38E6EEF2660BEE5A1521C58" xlink:to="loc_us-gaap_RangeMember_6C13FF0F83F3D0C7516BBEE5A152AFC0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_14E95A565B42499B99E8BEE5A1526A0C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_6C13FF0F83F3D0C7516BBEE5A152AFC0" xlink:to="loc_us-gaap_MinimumMember_14E95A565B42499B99E8BEE5A1526A0C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_B573EBBB729524D3808ABEE5A153A844" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_6C13FF0F83F3D0C7516BBEE5A152AFC0" xlink:to="loc_us-gaap_MaximumMember_B573EBBB729524D3808ABEE5A153A844" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_235F0BA86CCCC85A0062BEE5A15362EB" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_EC001DC078554F1B3700BEE5A152AF29" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_235F0BA86CCCC85A0062BEE5A15362EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F6C0E8BEEB03EEA3BD4DBEE5A154BAE3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_235F0BA86CCCC85A0062BEE5A15362EB" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F6C0E8BEEB03EEA3BD4DBEE5A154BAE3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_4B98ADCD6C97FA581A7BBEE5A154B38D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F6C0E8BEEB03EEA3BD4DBEE5A154BAE3" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_4B98ADCD6C97FA581A7BBEE5A154B38D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:label="loc_us-gaap_ComputerEquipmentMember_FC2FB49DDFA7D869D3A9BEE5A154F998" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F6C0E8BEEB03EEA3BD4DBEE5A154BAE3" xlink:to="loc_us-gaap_ComputerEquipmentMember_FC2FB49DDFA7D869D3A9BEE5A154F998" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_EvaluationUnitsMember" xlink:label="loc_ftnt_EvaluationUnitsMember_1AFF0A66788FD2F823CABEE5A154CBAB" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F6C0E8BEEB03EEA3BD4DBEE5A154BAE3" xlink:to="loc_ftnt_EvaluationUnitsMember_1AFF0A66788FD2F823CABEE5A154CBAB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_08808735113E256BEE73BEE5A1557B92" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_F6C0E8BEEB03EEA3BD4DBEE5A154BAE3" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_08808735113E256BEE73BEE5A1557B92" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D421010F34F0E9CB3C2BBEE5A1562DD4" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_EC001DC078554F1B3700BEE5A152AF29" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D421010F34F0E9CB3C2BBEE5A1562DD4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_11984710612FDCCDA9F1BEE5A156B732" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_D421010F34F0E9CB3C2BBEE5A1562DD4" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_11984710612FDCCDA9F1BEE5A156B732" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesRecentAccountingPronouncementsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_C98F89D830237E5A5DC5D3D89475C7C4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementEarlyAdoptionTable" xlink:label="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_0A6F85A082C4C39F528BD3D89475B545" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_C98F89D830237E5A5DC5D3D89475C7C4" xlink:to="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_0A6F85A082C4C39F528BD3D89475B545" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_FB8D62C4F70B01EB9DD8D3D894759A38" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_0A6F85A082C4C39F528BD3D89475B545" xlink:to="loc_us-gaap_RangeAxis_FB8D62C4F70B01EB9DD8D3D894759A38" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_90F6F942B59079DBD9F7D3D894750B9E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeAxis_FB8D62C4F70B01EB9DD8D3D894759A38" xlink:to="loc_us-gaap_RangeMember_90F6F942B59079DBD9F7D3D894750B9E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_E5C9D2FA8EA2E1C4B152D3D894755F47" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_90F6F942B59079DBD9F7D3D894750B9E" xlink:to="loc_us-gaap_MinimumMember_E5C9D2FA8EA2E1C4B152D3D894755F47" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_ABE2C16DE53E7FEA08E2D3D89476544A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_90F6F942B59079DBD9F7D3D894750B9E" xlink:to="loc_us-gaap_MaximumMember_ABE2C16DE53E7FEA08E2D3D89476544A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_AB5FA763F4BD7879CB05D3D89476055B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_0A6F85A082C4C39F528BD3D89475B545" xlink:to="loc_us-gaap_StatementScenarioAxis_AB5FA763F4BD7879CB05D3D89476055B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_9E2BD351E1EDE668C90BD3D894768A61" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementScenarioAxis_AB5FA763F4BD7879CB05D3D89476055B" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_9E2BD351E1EDE668C90BD3D894768A61" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioForecastMember" xlink:label="loc_us-gaap_ScenarioForecastMember_3CA78BE2D861B0351CCDD3D894762E3D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_9E2BD351E1EDE668C90BD3D894768A61" xlink:to="loc_us-gaap_ScenarioForecastMember_3CA78BE2D861B0351CCDD3D894762E3D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E600114DAA9F19F061F0D3D89476EF94" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_0A6F85A082C4C39F528BD3D89475B545" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E600114DAA9F19F061F0D3D89476EF94" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_E021E62EB755E78DD1C0D3D8947615EC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E600114DAA9F19F061F0D3D89476EF94" xlink:to="loc_us-gaap_TypeOfAdoptionMember_E021E62EB755E78DD1C0D3D8947615EC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingStandardsUpdate201602Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201602Member_604264AF2886B8A99DEAD3D89476E6DD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TypeOfAdoptionMember_E021E62EB755E78DD1C0D3D8947615EC" xlink:to="loc_us-gaap_AccountingStandardsUpdate201602Member_604264AF2886B8A99DEAD3D89476E6DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingStandardsUpdate201409Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201409Member_0DF59D97B2AFC0BCCCEFD3D89476CCD5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TypeOfAdoptionMember_E021E62EB755E78DD1C0D3D8947615EC" xlink:to="loc_us-gaap_AccountingStandardsUpdate201409Member_0DF59D97B2AFC0BCCCEFD3D89476CCD5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_C5E93075365E34B9335FD3D894762921" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_0A6F85A082C4C39F528BD3D89475B545" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_C5E93075365E34B9335FD3D894762921" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_77133E3675AF8A4E5C77D3D89476302E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_C5E93075365E34B9335FD3D894762921" xlink:to="loc_us-gaap_EquityComponentDomain_77133E3675AF8A4E5C77D3D89476302E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_81ABE469B1DAF45D2AA8D3D89476625F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityComponentDomain_77133E3675AF8A4E5C77D3D89476302E" xlink:to="loc_us-gaap_RetainedEarningsMember_81ABE469B1DAF45D2AA8D3D89476625F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionTable_0A6F85A082C4C39F528BD3D89475B545" xlink:to="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_ACE71BF84091382E28CFD3D894763D5C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_ACE71BF84091382E28CFD3D894763D5C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_7B37E864DE862FC63359D3D89477CF77" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_7B37E864DE862FC63359D3D89477CF77" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_0E2BD6D2178CE26DD0A4D3D894773C47" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_0E2BD6D2178CE26DD0A4D3D894773C47" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_5BBCC165EB2645B57E89D3D89477D076" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_NetIncomeLoss_5BBCC165EB2645B57E89D3D89477D076" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_A18E18CC1652E848516FD3D894772121" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_EarningsPerShareBasic_A18E18CC1652E848516FD3D894772121" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_D123CCF2A4A65A74EDBDD3D8947799CE" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_EarningsPerShareDiluted_D123CCF2A4A65A74EDBDD3D8947799CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_49F2931A94553B45BA4FD3D894776F93" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_49F2931A94553B45BA4FD3D894776F93" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:label="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_225CB7436775ADBD4F2ED3D894774BE1" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_DeferredTaxAssetsNetNoncurrent_225CB7436775ADBD4F2ED3D894774BE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_14B617D6A715B1D8CFDDD3D89477E8E2" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_14B617D6A715B1D8CFDDD3D89477E8E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification" xlink:label="loc_us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification_8A01D7A373903D85E596D3D894775815" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementEarlyAdoptionLineItems_56EE653A2A16E1FCEB92D3D89476126B" xlink:to="loc_us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification_8A01D7A373903D85E596D3D894775815" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesRevenueRecognitionDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_F86483E434BEA53FA229BBEB9C4FF9E8" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable" xlink:label="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_F1E95FE6051AB1D15FA4BBEB9C505D7D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_F86483E434BEA53FA229BBEB9C4FF9E8" xlink:to="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_F1E95FE6051AB1D15FA4BBEB9C505D7D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_3B3540485BC1890448F0BBEB9C5096AA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_F1E95FE6051AB1D15FA4BBEB9C505D7D" xlink:to="loc_us-gaap_RangeAxis_3B3540485BC1890448F0BBEB9C5096AA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_F9DF10B838973FB26B16BBEB9C505716" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeAxis_3B3540485BC1890448F0BBEB9C5096AA" xlink:to="loc_us-gaap_RangeMember_F9DF10B838973FB26B16BBEB9C505716" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_DE4E305CEF75487519D5BBEB9C504B44" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_F9DF10B838973FB26B16BBEB9C505716" xlink:to="loc_us-gaap_MinimumMember_DE4E305CEF75487519D5BBEB9C504B44" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_4D96ADB27F6D21EB38ECBBEB9C50DB45" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_F9DF10B838973FB26B16BBEB9C505716" xlink:to="loc_us-gaap_MaximumMember_4D96ADB27F6D21EB38ECBBEB9C50DB45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems" xlink:label="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_3EAA452A6748C8A1F2F2BBEB9C50A0F8" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_F1E95FE6051AB1D15FA4BBEB9C505D7D" xlink:to="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_3EAA452A6748C8A1F2F2BBEB9C50A0F8" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_RevenueRecognitionPeriod" xlink:label="loc_ftnt_RevenueRecognitionPeriod_93E3346B4E286FDB30FEBBEB9C50E8F1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_3EAA452A6748C8A1F2F2BBEB9C50A0F8" xlink:to="loc_ftnt_RevenueRecognitionPeriod_93E3346B4E286FDB30FEBBEB9C50E8F1" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesStockBasedCompensationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_402985C2EB84822AA6E6B9809CB352D6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F3A726D42A4B3FEE9FE6B9809CB3ADAD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_402985C2EB84822AA6E6B9809CB352D6" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F3A726D42A4B3FEE9FE6B9809CB3ADAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_250D54DE987403972496B9809CB30535" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F3A726D42A4B3FEE9FE6B9809CB3ADAD" xlink:to="loc_us-gaap_AwardTypeAxis_250D54DE987403972496B9809CB30535" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7120C732EAC0AE5F675FB9809CB3788C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_250D54DE987403972496B9809CB30535" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7120C732EAC0AE5F675FB9809CB3788C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VestingAxis" xlink:label="loc_us-gaap_VestingAxis_83621915C74DA4E69213B9809CB964F8" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F3A726D42A4B3FEE9FE6B9809CB3ADAD" xlink:to="loc_us-gaap_VestingAxis_83621915C74DA4E69213B9809CB964F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VestingDomain" xlink:label="loc_us-gaap_VestingDomain_DF8C7AE01D4EB6B807CBB9809CB97B22" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_VestingAxis_83621915C74DA4E69213B9809CB964F8" xlink:to="loc_us-gaap_VestingDomain_DF8C7AE01D4EB6B807CBB9809CB97B22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_25F5424FC44BCCCC33E7B9809CB96E82" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_F3A726D42A4B3FEE9FE6B9809CB3ADAD" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_25F5424FC44BCCCC33E7B9809CB96E82" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_D44F4B9ED5EC6BC7E852B9809CB9BA1F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_25F5424FC44BCCCC33E7B9809CB96E82" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_D44F4B9ED5EC6BC7E852B9809CB9BA1F" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_2D9C4C888A0988281C04B5D7640B8AD3" xlink:type="locator" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleofEstimatedUsefulLivesofPropertyPlantandEquipmentTableTextBlock" xlink:label="loc_ftnt_ScheduleofEstimatedUsefulLivesofPropertyPlantandEquipmentTableTextBlock_126446598BEA7F6BDC87B5D7640BBDA4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_2D9C4C888A0988281C04B5D7640B8AD3" xlink:to="loc_ftnt_ScheduleofEstimatedUsefulLivesofPropertyPlantandEquipmentTableTextBlock_126446598BEA7F6BDC87B5D7640BBDA4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock_153CFC79B37B69B12ACAB5D7640B5E30" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_2D9C4C888A0988281C04B5D7640B8AD3" xlink:to="loc_us-gaap_ScheduleOfNotionalAmountsOfOutstandingDerivativePositionsTableTextBlock_153CFC79B37B69B12ACAB5D7640B5E30" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/SummaryOfSignificantAccountingPoliciesWarrantiesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_FCA1CCA85D6030F9B920BBEB9BE402D2" xlink:type="locator" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_ScheduleOfWarrantiesTable" xlink:label="loc_ftnt_ScheduleOfWarrantiesTable_1A44716A424E0737E0B6BBEB9BE4C8E8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_FCA1CCA85D6030F9B920BBEB9BE402D2" xlink:to="loc_ftnt_ScheduleOfWarrantiesTable_1A44716A424E0737E0B6BBEB9BE4C8E8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductOrServiceAxis" xlink:label="loc_us-gaap_ProductOrServiceAxis_B96CD91641BB1D1B51F4BBEB9BE43E15" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfWarrantiesTable_1A44716A424E0737E0B6BBEB9BE4C8E8" xlink:to="loc_us-gaap_ProductOrServiceAxis_B96CD91641BB1D1B51F4BBEB9BE43E15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductsAndServicesDomain" xlink:label="loc_us-gaap_ProductsAndServicesDomain_140D5E58139D571A293CBBEB9BE4D416" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ProductOrServiceAxis_B96CD91641BB1D1B51F4BBEB9BE43E15" xlink:to="loc_us-gaap_ProductsAndServicesDomain_140D5E58139D571A293CBBEB9BE4D416" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_HardwareProductWarrantyMember" xlink:label="loc_ftnt_HardwareProductWarrantyMember_751353DA013E07F8E068BBEB9BE4816C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ProductsAndServicesDomain_140D5E58139D571A293CBBEB9BE4D416" xlink:to="loc_ftnt_HardwareProductWarrantyMember_751353DA013E07F8E068BBEB9BE4816C" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_SoftwareProductWarrantyMember" xlink:label="loc_ftnt_SoftwareProductWarrantyMember_8C620259FAAAC13B9402BBEB9BE40794" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ProductsAndServicesDomain_140D5E58139D571A293CBBEB9BE4D416" xlink:to="loc_ftnt_SoftwareProductWarrantyMember_8C620259FAAAC13B9402BBEB9BE40794" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_WarrantiesLineItems" xlink:label="loc_ftnt_WarrantiesLineItems_2B4CB6566135FB1772DFBBEB9BE461F6" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_ScheduleOfWarrantiesTable_1A44716A424E0737E0B6BBEB9BE4C8E8" xlink:to="loc_ftnt_WarrantiesLineItems_2B4CB6566135FB1772DFBBEB9BE461F6" xlink:type="arc" />
    <link:loc xlink:href="ftnt-20171231.xsd#ftnt_WarrantyLength" xlink:label="loc_ftnt_WarrantyLength_EBEAE5A44ECCF4B4CE68BBEB9BE4B519" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_ftnt_WarrantiesLineItems_2B4CB6566135FB1772DFBBEB9BE461F6" xlink:to="loc_ftnt_WarrantyLength_EBEAE5A44ECCF4B4CE68BBEB9BE4B519" xlink:type="arc" />
  </link:presentationLink>
</link:linkbase>
