<?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>0001418649</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>909 Kifer Road</ns2:street1>
                <ns2:city>Sunnyvale</ns2:city>
                <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                <ns2:zipCode>94086</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>4082357700</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>KEITH JENSEN</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <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>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>21900</noOfUnitsSold>
            <aggregateMarketValue>2012172.00</aggregateMarketValue>
            <noOfUnitsOutstanding>766452698</noOfUnitsOutstanding>
            <approxSaleDate>11/19/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/19/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>17650</amountOfSecuritiesAcquired>
            <paymentDate>11/19/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/01/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>4250</amountOfSecuritiesAcquired>
            <paymentDate>11/01/2024</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for KEITH JENSEN</name>
                <address>
                    <ns2:street1>909 Kifer Road</ns2:street1>
                    <ns2:city>Sunnyvale</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94086</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>11/08/2024</saleDate>
            <amountOfSecuritiesSold>56705</amountOfSecuritiesSold>
            <grossProceeds>4840421.53</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for KEITH JENSEN</name>
                <address>
                    <ns2:street1>909 Kifer Road</ns2:street1>
                    <ns2:city>Sunnyvale</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94086</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>08/27/2024</saleDate>
            <amountOfSecuritiesSold>11985</amountOfSecuritiesSold>
            <grossProceeds>905464.35</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for KEITH JENSEN</name>
                <address>
                    <ns2:street1>909 Kifer Road</ns2:street1>
                    <ns2:city>Sunnyvale</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94086</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>08/20/2024</saleDate>
            <amountOfSecuritiesSold>4250</amountOfSecuritiesSold>
            <grossProceeds>321636.18</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale.&#13;
</remarks>
        <noticeSignature>
            <noticeDate>11/19/2024</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>03/06/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Keith Jensen</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
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144
0001418649
XXXXXXXX
LIVE
0001262039
FORTINET INC
001-34511
909 Kifer Road
Sunnyvale
CA
94086
4082357700
KEITH JENSEN
Officer
COMMON
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
21900
2012172.00
766452698
11/19/2024
NASDAQ
Common
11/19/2024
Exercise of Stock Options
Issuer
N
17650
11/19/2024
Cash
Common
11/01/2024
Restricted Stock Units
Issuer
N
4250
11/01/2024
N/A
N
10b5-1 Sales for KEITH JENSEN
909 Kifer Road
Sunnyvale
CA
94086
COMMON
11/08/2024
56705
4840421.53
10b5-1 Sales for KEITH JENSEN
909 Kifer Road
Sunnyvale
CA
94086
COMMON
08/27/2024
11985
905464.35
10b5-1 Sales for KEITH JENSEN
909 Kifer Road
Sunnyvale
CA
94086
COMMON
08/20/2024
4250
321636.18
The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale.
11/19/2024
03/06/2024
/s/ Keith Jensen