<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e85ac-b5d9-7566-857b-ba39d408ad68,g:62512421-af0d-499a-a8a3-6cd324d79e8d-->
<link:linkbase 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" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://www.fortinet.com/role/DocumentAndEntityInformation" xlink:type="simple" xlink:href="ftnt-20260612.xsd#DocumentAndEntityInformation"/>
  <link:presentationLink xlink:role="http://www.fortinet.com/role/DocumentAndEntityInformation" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CoverAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019e85ac-b5d9-7d96-8ae2-89d9ead030b0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_DocumentType_019e85ac-b5d9-7d96-8ae2-89d9ead030b0" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019e85ac-b5d9-7b58-9ef6-7964679bda99" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_DocumentPeriodEndDate_019e85ac-b5d9-7b58-9ef6-7964679bda99" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019e85ac-b5d9-7430-bcae-7b2ae1a06172" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:presentationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityRegistrantName_019e85ac-b5d9-7430-bcae-7b2ae1a06172" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019e85ac-b5d9-7a8a-beef-9e8ce5577c7b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:presentationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019e85ac-b5d9-7a8a-beef-9e8ce5577c7b" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019e85ac-b5d9-74c2-9391-07716fbdbee9" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:presentationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityFileNumber_019e85ac-b5d9-74c2-9391-07716fbdbee9" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019e85ac-b5d9-7739-8dfe-8b2ba1555b99" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:presentationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityTaxIdentificationNumber_019e85ac-b5d9-7739-8dfe-8b2ba1555b99" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019e85ac-b5d9-7679-93fc-623dfd77dbd5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:presentationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityAddressAddressLine1_019e85ac-b5d9-7679-93fc-623dfd77dbd5" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019e85ac-b5d9-7efe-a8ce-8e78077f03c8" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:presentationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityAddressCityOrTown_019e85ac-b5d9-7efe-a8ce-8e78077f03c8" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019e85ac-b5d9-7b33-89ee-c1b2f8c526b8" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:presentationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityAddressStateOrProvince_019e85ac-b5d9-7b33-89ee-c1b2f8c526b8" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019e85ac-b5d9-7439-82b8-ce2457a95f37" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:presentationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityAddressPostalZipCode_019e85ac-b5d9-7439-82b8-ce2457a95f37" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019e85ac-b5d9-7650-b57d-40156268ba94" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:presentationArc order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_CityAreaCode_019e85ac-b5d9-7650-b57d-40156268ba94" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019e85ac-b5d9-7547-9047-52283767fc10" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:presentationArc order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_LocalPhoneNumber_019e85ac-b5d9-7547-9047-52283767fc10" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_019e85ac-b5d9-790d-a3fc-01bcec73f13d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_WrittenCommunications"/>
    <link:presentationArc order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_WrittenCommunications_019e85ac-b5d9-790d-a3fc-01bcec73f13d" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_019e85ac-b5d9-7bdf-b330-d264816d60fc" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SolicitingMaterial"/>
    <link:presentationArc order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_SolicitingMaterial_019e85ac-b5d9-7bdf-b330-d264816d60fc" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_019e85ac-b5d9-7057-a222-7027c7900e84" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementTenderOffer"/>
    <link:presentationArc order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_PreCommencementTenderOffer_019e85ac-b5d9-7057-a222-7027c7900e84" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_019e85ac-b5d9-7aa2-ad14-7c9430a83c22" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:presentationArc order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_019e85ac-b5d9-7aa2-ad14-7c9430a83c22" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019e85ac-b5d9-71da-9b45-33d0bf35fa93" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:presentationArc order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_Security12bTitle_019e85ac-b5d9-71da-9b45-33d0bf35fa93" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019e85ac-b5d9-7966-a9c2-4102cc8e9094" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:presentationArc order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_TradingSymbol_019e85ac-b5d9-7966-a9c2-4102cc8e9094" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019e85ac-b5d9-7a8b-9ce6-934bdde7e78f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:presentationArc order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_SecurityExchangeName_019e85ac-b5d9-7a8b-9ce6-934bdde7e78f" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019e85ac-b5d9-7fb4-96c2-a3ee6e803df5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:presentationArc order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityEmergingGrowthCompany_019e85ac-b5d9-7fb4-96c2-a3ee6e803df5" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019e85ac-b5d9-7ade-920e-38b13e16f6f5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:presentationArc order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_EntityCentralIndexKey_019e85ac-b5d9-7ade-920e-38b13e16f6f5" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019e85ac-b5d9-7440-851d-0ffd4746b2c4" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:presentationArc order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019e85ac-b5d9-737e-94c0-ed223c457aaf" xlink:to="loc_dei_AmendmentFlag_019e85ac-b5d9-7440-851d-0ffd4746b2c4" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </link:presentationLink>
</link:linkbase>
