<?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>0001346629</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0000798354</issuerCik>
            <issuerName>FISERV, INC.</issuerName>
            <secFileNumber>001-38962</secFileNumber>
            <issuerAddress>
                <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                <ns2:city>Milwaukee</ns2:city>
                <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                <ns2:zipCode>53203</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>262- 879-5000</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>FRANK J BISIGNANO </nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>former affiliate</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>367</noOfUnitsSold>
            <aggregateMarketValue>59041.13</aggregateMarketValue>
            <noOfUnitsOutstanding>554433824</noOfUnitsOutstanding>
            <approxSaleDate>05/27/2025</approxSaleDate>
            <securitiesExchangeName>NYSE</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/14/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Gift from Affiliate</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Frank Bisignano</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>Y</isGiftTransaction>
            <donarAcquiredDate>03/16/2021</donarAcquiredDate>
            <amountOfSecuritiesAcquired>154</amountOfSecuritiesAcquired>
            <natureOfPayment>NA</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/24/2025</acquiredDate>
            <natureOfAcquisitionTransaction>Gift from Affiliate</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Frank Bisignano</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>Y</isGiftTransaction>
            <donarAcquiredDate>02/16/2016</donarAcquiredDate>
            <amountOfSecuritiesAcquired>166</amountOfSecuritiesAcquired>
            <natureOfPayment>NA</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>11/15/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Gift from Affiliate</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Frank Bisignano</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>Y</isGiftTransaction>
            <donarAcquiredDate>12/01/2021</donarAcquiredDate>
            <amountOfSecuritiesAcquired>47</amountOfSecuritiesAcquired>
            <natureOfPayment>NA</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/20/2025</saleDate>
            <amountOfSecuritiesSold>100000</amountOfSecuritiesSold>
            <grossProceeds>16690770.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>Frank Bisignano</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Covered Call</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>5845</amountOfSecuritiesSold>
            <grossProceeds>19692.71</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>332</amountOfSecuritiesSold>
            <grossProceeds>55977.26</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>6438</amountOfSecuritiesSold>
            <grossProceeds>1085486.72</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>37573</amountOfSecuritiesSold>
            <grossProceeds>6335040.75</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>55657</amountOfSecuritiesSold>
            <grossProceeds>9384115.27</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO 2015 GRAT</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>28143</amountOfSecuritiesSold>
            <grossProceeds>4745953.91</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO 2015 GRAT</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>2418</amountOfSecuritiesSold>
            <grossProceeds>407764.51</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO 2015 GRAT</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>28143</amountOfSecuritiesSold>
            <grossProceeds>4745934.21</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO 2015 GRAT</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>2418</amountOfSecuritiesSold>
            <grossProceeds>407762.82</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO 2015 GRAT</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>28143</amountOfSecuritiesSold>
            <grossProceeds>4745959.53</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>FRANK J BISIGNANO 2015 GRAT</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/19/2025</saleDate>
            <amountOfSecuritiesSold>2418</amountOfSecuritiesSold>
            <grossProceeds>407764.99</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>Frank Bisignano</name>
                <address>
                    <ns2:street1>600 N. Vel R. Phillips Avenue</ns2:street1>
                    <ns2:city>Milwaukee</ns2:city>
                    <ns2:stateOrCountry>WI</ns2:stateOrCountry>
                    <ns2:zipCode>53203</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/16/2025</saleDate>
            <amountOfSecuritiesSold>100000</amountOfSecuritiesSold>
            <grossProceeds>16683943.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>05/27/2025</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Frank J Bisignano</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 13689}]
144
0001346629
XXXXXXXX
LIVE
0000798354
FISERV, INC.
001-38962
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
262- 879-5000
FRANK J BISIGNANO
former affiliate
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
367
59041.13
554433824
05/27/2025
NYSE
Common
08/14/2024
Gift from Affiliate
Frank Bisignano
Y
03/16/2021
154
NA
Common
02/24/2025
Gift from Affiliate
Frank Bisignano
Y
02/16/2016
166
NA
Common
11/15/2024
Gift from Affiliate
Frank Bisignano
Y
12/01/2021
47
NA
N
FRANK J BISIGNANO
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/20/2025
100000
16690770.00
Frank Bisignano
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Covered Call
05/19/2025
5845
19692.71
FRANK J BISIGNANO
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
332
55977.26
FRANK J BISIGNANO
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
6438
1085486.72
FRANK J BISIGNANO
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
37573
6335040.75
FRANK J BISIGNANO
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
55657
9384115.27
FRANK J BISIGNANO 2015 GRAT
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
28143
4745953.91
FRANK J BISIGNANO 2015 GRAT
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
2418
407764.51
FRANK J BISIGNANO 2015 GRAT
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
28143
4745934.21
FRANK J BISIGNANO 2015 GRAT
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
2418
407762.82
FRANK J BISIGNANO 2015 GRAT
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
28143
4745959.53
FRANK J BISIGNANO 2015 GRAT
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/19/2025
2418
407764.99
Frank Bisignano
600 N. Vel R. Phillips Avenue
Milwaukee
WI
53203
Common
05/16/2025
100000
16683943.00
05/27/2025
/s/ Frank J Bisignano