content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
      <headerData>
          <submissionType>144</submissionType>
          <filerInfo>
              <filer>
                  <filerCredentials>
                      <cik>0001475586</cik>
                      <ccc>XXXXXXXX</ccc>
                  </filerCredentials>
              </filer>
              <liveTestFlag>LIVE</liveTestFlag>
  
  
  
          </filerInfo>
      </headerData>
      <formData>
          <issuerInfo>
              <issuerCik>0001262039</issuerCik>
              <issuerName>FORTINET INC</issuerName>
              <secFileNumber>001-34511</secFileNumber>
              <issuerAddress>
                  <ns2:street1>899 Kifer Road</ns2:street1>
                  <ns2:city>Sunnyvale</ns2:city>
                  <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                  <ns2:zipCode>94006</ns2:zipCode>
              </issuerAddress>
              <issuerContactPhone>4082357700</issuerContactPhone>
              <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>MICHAEL XIE</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
              <relationshipsToIssuer>
                  <relationshipToIssuer>Director</relationshipToIssuer>
                  <relationshipToIssuer>Officer</relationshipToIssuer>
              </relationshipsToIssuer>
          </issuerInfo>
          <securitiesInformation>
              <securitiesClassTitle>Common</securitiesClassTitle>
              <brokerOrMarketmakerDetails>
                  <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                  <address>
                      <ns2:street1>1 New York Plaza</ns2:street1>
                      <ns2:street2>38th Fl.</ns2:street2>
                      <ns2:city>New York</ns2:city>
                      <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                      <ns2:zipCode>10004</ns2:zipCode>
                  </address>
              </brokerOrMarketmakerDetails>
              <noOfUnitsSold>25885</noOfUnitsSold>
              <aggregateMarketValue>1328418.20</aggregateMarketValue>
              <noOfUnitsOutstanding>767909603</noOfUnitsOutstanding>
              <approxSaleDate>12/08/2023</approxSaleDate>
              <securitiesExchangeName>NASDAQ</securitiesExchangeName>
          </securitiesInformation>
          <securitiesToBeSold>
              <securitiesClassTitle>Common</securitiesClassTitle>
              <acquiredDate>12/31/2003</acquiredDate>
              <natureOfAcquisitionTransaction>Founders Shares</natureOfAcquisitionTransaction>
              <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
              <isGiftTransaction>N</isGiftTransaction>
              <amountOfSecuritiesAcquired>20000</amountOfSecuritiesAcquired>
              <paymentDate>12/31/2003</paymentDate>
              <natureOfPayment>N/A</natureOfPayment>
          </securitiesToBeSold>
          <securitiesToBeSold>
              <securitiesClassTitle>Common</securitiesClassTitle>
              <acquiredDate>11/01/2023</acquiredDate>
              <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
              <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
              <isGiftTransaction>N</isGiftTransaction>
              <amountOfSecuritiesAcquired>5885</amountOfSecuritiesAcquired>
              <paymentDate>11/01/2023</paymentDate>
              <natureOfPayment>N/A</natureOfPayment>
          </securitiesToBeSold>
          <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
          <securitiesSoldInPast3Months>
              <sellerDetails>
                  <name>THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY</name>
                  <address>
                      <ns2:street1>326 Galvez Street</ns2:street1>
                      <ns2:city>Stanford</ns2:city>
                      <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                      <ns2:zipCode>94305</ns2:zipCode>
                  </address>
              </sellerDetails>
              <securitiesClassTitle>Common</securitiesClassTitle>
              <saleDate>11/22/2023</saleDate>
              <amountOfSecuritiesSold>92400</amountOfSecuritiesSold>
              <grossProceeds>4901762.27</grossProceeds>
          </securitiesSoldInPast3Months>
          <noticeSignature>
              <noticeDate>12/08/2023</noticeDate>
              <planAdoptionDates>
                  <planAdoptionDate>09/08/2023</planAdoptionDate>
              </planAdoptionDates>
              <signature>/s/ Michael Xie</signature>
          </noticeSignature>
      </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 4668}]
text: 144
  0001475586
  XXXXXXXX
  LIVE
  0001262039
  FORTINET INC
  001-34511
  899 Kifer Road
  Sunnyvale
  CA
  94006
  4082357700
  MICHAEL XIE
  Director
  Officer
  Common
  Morgan Stanley Smith Barney LLC Executive Financial Services
  1 New York Plaza
  38th Fl.
  New York
  NY
  10004
  25885
  1328418.20
  767909603
  12/08/2023
  NASDAQ
  Common
  12/31/2003
  Founders Shares
  Issuer
  N
  20000
  12/31/2003
  N/A
  Common
  11/01/2023
  Restricted Stock Units
  Issuer
  N
  5885
  11/01/2023
  N/A
  N
  THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY
  326 Galvez Street
  Stanford
  CA
  94305
  Common
  11/22/2023
  92400
  4901762.27
  12/08/2023
  09/08/2023
  /s/ Michael Xie