<?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>0002000932</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001288847</issuerCik>
            <issuerName>Five9, Inc.</issuerName>
            <secFileNumber>001-36383</secFileNumber>
            <issuerAddress>
                <ns2:street1>3001 Bishop Drive, Suite 350</ns2:street1>
                <ns2:city>San Ramon</ns2:city>
                <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                <ns2:zipCode>94583</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>9252012000</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>ANDREW DIGNAN </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>1400</noOfUnitsSold>
            <aggregateMarketValue>37072.00</aggregateMarketValue>
            <noOfUnitsOutstanding>76272014</noOfUnitsOutstanding>
            <approxSaleDate>07/01/2025</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/03/2023</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1400</amountOfSecuritiesAcquired>
            <paymentDate>06/03/2023</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for  ANDREW DIGNAN &amp; JODI DIGNAN JT TEN</name>
                <address>
                    <ns2:street1>3001 Bishop Drive, Suite 350</ns2:street1>
                    <ns2:city>San Ramon</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94583</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>06/05/2025</saleDate>
            <amountOfSecuritiesSold>700</amountOfSecuritiesSold>
            <grossProceeds>20461.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for  ANDREW DIGNAN &amp; JODI DIGNAN JT TEN</name>
                <address>
                    <ns2:street1>3001 Bishop Drive, Suite 350</ns2:street1>
                    <ns2:city>San Ramon</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94583</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>06/04/2025</saleDate>
            <amountOfSecuritiesSold>2667</amountOfSecuritiesSold>
            <grossProceeds>74943.91</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>ANDREW DIGNAN</name>
                <address>
                    <ns2:street1>3001 Bishop Drive, Suite 350</ns2:street1>
                    <ns2:city>San Ramon</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94583</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>06/04/2025</saleDate>
            <amountOfSecuritiesSold>2178</amountOfSecuritiesSold>
            <grossProceeds>61593.84</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for  ANDREW DIGNAN &amp; JODI DIGNAN JT TEN</name>
                <address>
                    <ns2:street1>3001 Bishop Drive, Suite 350</ns2:street1>
                    <ns2:city>San Ramon</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>94583</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/01/2025</saleDate>
            <amountOfSecuritiesSold>700</amountOfSecuritiesSold>
            <grossProceeds>17864.35</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>The securities to be sold were acquired upon the vesting of restricted stock units during the period of 06/03/2023 through 06/03/2024.
</remarks>
        <noticeSignature>
            <noticeDate>07/01/2025</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>12/10/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Andrew Dignan</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 6386}]
144
0002000932
XXXXXXXX
LIVE
0001288847
Five9, Inc.
001-36383
3001 Bishop Drive, Suite 350
San Ramon
CA
94583
9252012000
ANDREW DIGNAN
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
1400
37072.00
76272014
07/01/2025
NASDAQ
Common
06/03/2023
Restricted Stock Units
Issuer
N
1400
06/03/2023
N/A
N
10b5-1 Sales for  ANDREW DIGNAN & JODI DIGNAN JT TEN
3001 Bishop Drive, Suite 350
San Ramon
CA
94583
Common
06/05/2025
700
20461.00
10b5-1 Sales for  ANDREW DIGNAN & JODI DIGNAN JT TEN
3001 Bishop Drive, Suite 350
San Ramon
CA
94583
Common
06/04/2025
2667
74943.91
ANDREW DIGNAN
3001 Bishop Drive, Suite 350
San Ramon
CA
94583
Common
06/04/2025
2178
61593.84
10b5-1 Sales for  ANDREW DIGNAN & JODI DIGNAN JT TEN
3001 Bishop Drive, Suite 350
San Ramon
CA
94583
Common
05/01/2025
700
17864.35
The securities to be sold were acquired upon the vesting of restricted stock units during the period of 06/03/2023 through 06/03/2024.
07/01/2025
12/10/2024
/s/ Andrew Dignan