<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-09-08</periodOfReport>

    <issuer>
        <issuerCik>0001473597</issuerCik>
        <issuerName>STR HOLDINGS, INC.</issuerName>
        <issuerTradingSymbol>STRI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001443957</rptOwnerCik>
            <rptOwnerName>Jilot Dennis L.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>18 CRAFTSMAN ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>EAST WINDSOR</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06088</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, Par Value $0.01 Per Share</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2014-09-08</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2014-09-08</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value>E</value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>625844</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>321656</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Jilot Family Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, Par Value $0.01 Per Share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>92772</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, Par Value $0.01 Per Share</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>67816</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Dennis Jilot GRAT 2</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, Par Value $0.01 Per Share</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>67816</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Linda Jilot GRAT 2</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Held by The Dennis L. and Linda L. Jilot Family Trust, of which Mr. Jilot is a co-trustee and beneficiary.</footnote>
        <footnote id="F2">Held by Dennis L. Jilot, as Trustee of The Dennis L. Jilot GRAT No. 2 Trust Agreement dated April 16, 2012.</footnote>
        <footnote id="F3">Held by Linda L. Jilot, as Trustee of The Linda L. Jilot GRAT No. 2 Trust Agreement dated April 16, 2012. The reporting person's spouse is trustee of the trust. The reporting person disclaims ownership of such securities, and this report should not be deemed an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purposes.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Joseph C. Radziewicz, Attorney-in-fact</signatureName>
        <signatureDate>2014-09-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
