<?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>0001489550</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001633978</issuerCik>
            <issuerName>LUMENTUM HOLDINGS INC.</issuerName>
            <secFileNumber>001-36861</secFileNumber>
            <issuerAddress>
                <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                <ns2:city>San Jose</ns2:city>
                <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                <ns2:zipCode>95131</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>(408) 546-5483</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>WUPEN YUEN</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>289</noOfUnitsSold>
            <aggregateMarketValue>21929.32</aggregateMarketValue>
            <noOfUnitsOutstanding>69400000</noOfUnitsOutstanding>
            <approxSaleDate>05/19/2025</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>05/15/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>289</amountOfSecuritiesAcquired>
            <paymentDate>05/15/2024</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/16/2025</saleDate>
            <amountOfSecuritiesSold>252</amountOfSecuritiesSold>
            <grossProceeds>19650.96</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/16/2025</saleDate>
            <amountOfSecuritiesSold>38</amountOfSecuritiesSold>
            <grossProceeds>2963.24</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2025</saleDate>
            <amountOfSecuritiesSold>290</amountOfSecuritiesSold>
            <grossProceeds>22292.30</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2025</saleDate>
            <amountOfSecuritiesSold>481</amountOfSecuritiesSold>
            <grossProceeds>36974.47</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2025</saleDate>
            <amountOfSecuritiesSold>812</amountOfSecuritiesSold>
            <grossProceeds>62418.44</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2025</saleDate>
            <amountOfSecuritiesSold>300</amountOfSecuritiesSold>
            <grossProceeds>23061.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2025</saleDate>
            <amountOfSecuritiesSold>256</amountOfSecuritiesSold>
            <grossProceeds>19678.72</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2025</saleDate>
            <amountOfSecuritiesSold>1266</amountOfSecuritiesSold>
            <grossProceeds>97317.42</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2025</saleDate>
            <amountOfSecuritiesSold>735</amountOfSecuritiesSold>
            <grossProceeds>56499.45</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/15/2025</saleDate>
            <amountOfSecuritiesSold>576</amountOfSecuritiesSold>
            <grossProceeds>44277.12</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/14/2025</saleDate>
            <amountOfSecuritiesSold>1604</amountOfSecuritiesSold>
            <grossProceeds>120203.76</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/14/2025</saleDate>
            <amountOfSecuritiesSold>826</amountOfSecuritiesSold>
            <grossProceeds>61900.44</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/14/2025</saleDate>
            <amountOfSecuritiesSold>748</amountOfSecuritiesSold>
            <grossProceeds>56055.12</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/14/2025</saleDate>
            <amountOfSecuritiesSold>806</amountOfSecuritiesSold>
            <grossProceeds>60401.64</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/14/2025</saleDate>
            <amountOfSecuritiesSold>22</amountOfSecuritiesSold>
            <grossProceeds>1648.68</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/14/2025</saleDate>
            <amountOfSecuritiesSold>420</amountOfSecuritiesSold>
            <grossProceeds>31474.80</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>WUPEN YUEN</name>
                <address>
                    <ns2:street1>1001 Ridder Park Drive</ns2:street1>
                    <ns2:city>San Jose</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>95131</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>05/13/2025</saleDate>
            <amountOfSecuritiesSold>4426</amountOfSecuritiesSold>
            <grossProceeds>317786.80</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>05/19/2025</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>02/11/2025</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Wupen Yuen</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
