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        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001234673</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>ALAN S. LOWE</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Director</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>20000</noOfUnitsSold>
            <aggregateMarketValue>1769400.00</aggregateMarketValue>
            <noOfUnitsOutstanding>69400000</noOfUnitsOutstanding>
            <approxSaleDate>06/18/2025</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/31/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>ISSUER</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>8280</amountOfSecuritiesAcquired>
            <paymentDate>08/31/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>08/22/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Performance Shares</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>ISSUER</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>11720</amountOfSecuritiesAcquired>
            <paymentDate>08/22/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>ALAN S. LOWE</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>06/04/2025</saleDate>
            <amountOfSecuritiesSold>4937</amountOfSecuritiesSold>
            <grossProceeds>412634.46</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>ALAN S. LOWE</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>06/04/2025</saleDate>
            <amountOfSecuritiesSold>3872</amountOfSecuritiesSold>
            <grossProceeds>323621.76</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>ALAN S. LOWE</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>06/04/2025</saleDate>
            <amountOfSecuritiesSold>1191</amountOfSecuritiesSold>
            <grossProceeds>99543.78</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>06/18/2025</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>11/20/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Alan Scott Lowe</signature>
        </noticeSignature>
    </formData>
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144
0001234673
XXXXXXXX
LIVE
0001633978
LUMENTUM HOLDINGS INC.
001-36861
1001 Ridder Park Drive
San Jose
CA
95131
(408) 546-5483
ALAN S. LOWE
Director
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
20000
1769400.00
69400000
06/18/2025
NASDAQ
Common
08/31/2022
Restricted Stock
ISSUER
N
8280
08/31/2022
Not Applicable
Common
08/22/2022
Performance Shares
ISSUER
N
11720
08/22/2022
Not Applicable
N
ALAN S. LOWE
1001 Ridder Park Drive
San Jose
CA
95131
Common
06/04/2025
4937
412634.46
ALAN S. LOWE
1001 Ridder Park Drive
San Jose
CA
95131
Common
06/04/2025
3872
323621.76
ALAN S. LOWE
1001 Ridder Park Drive
San Jose
CA
95131
Common
06/04/2025
1191
99543.78
06/18/2025
11/20/2024
/s/ Alan Scott Lowe