<SEC-DOCUMENT>0001567619-21-014086.txt : 20210728
<SEC-HEADER>0001567619-21-014086.hdr.sgml : 20210728
<ACCEPTANCE-DATETIME>20210728122609
ACCESSION NUMBER:		0001567619-21-014086
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210727
FILED AS OF DATE:		20210728
DATE AS OF CHANGE:		20210728

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Goldstein Robert Thomas
		CENTRAL INDEX KEY:			0001872785

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40619
		FILM NUMBER:		211121280

	MAIL ADDRESS:	
		STREET 1:		19 PARK AVENUE
		CITY:			RUTHERFORD
		STATE:			NJ
		ZIP:			07070

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Blue Foundry Bancorp
		CENTRAL INDEX KEY:			0001846017
		STANDARD INDUSTRIAL CLASSIFICATION:	SAVINGS INSTITUTIONS, NOT FEDERALLY CHARTERED [6036]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		19 PARK AVENUE
		CITY:			RUTHERFORD
		STATE:			NJ
		ZIP:			07070
		BUSINESS PHONE:		201-939-6600

	MAIL ADDRESS:	
		STREET 1:		19 PARK AVENUE
		CITY:			RUTHERFORD
		STATE:			NJ
		ZIP:			07070
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-07-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001846017</issuerCik>
        <issuerName>Blue Foundry Bancorp</issuerName>
        <issuerTradingSymbol>BLFY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001872785</rptOwnerCik>
            <rptOwnerName>Goldstein Robert Thomas</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>19 PARK AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RUTHERFORD</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07070</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-07-27</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.36</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10387</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Zachary Davis, pursuant to Power of Attorney</signatureName>
        <signatureDate>2021-07-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
