<SEC-DOCUMENT>0000709283-21-000035.txt : 20210716
<SEC-HEADER>0000709283-21-000035.hdr.sgml : 20210716
<ACCEPTANCE-DATETIME>20210716151533
ACCESSION NUMBER:		0000709283-21-000035
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210714
FILED AS OF DATE:		20210716
DATE AS OF CHANGE:		20210716

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lerner James J
		CENTRAL INDEX KEY:			0001602567

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13449
		FILM NUMBER:		211095342

	MAIL ADDRESS:	
		STREET 1:		C/O SEAGATE TECHNOLOGY PLC
		STREET 2:		10200 S. DEANZA BLVD.
		CITY:			CUPERTINO
		STATE:			CA
		ZIP:			95014

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			QUANTUM CORP /DE/
		CENTRAL INDEX KEY:			0000709283
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER STORAGE DEVICES [3572]
		IRS NUMBER:				942665054
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		224 AIRPORT PARKWAY
		STREET 2:		SUITE 550
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110
		BUSINESS PHONE:		408 944 4000

	MAIL ADDRESS:	
		STREET 1:		224 AIRPORT PARKWAY
		STREET 2:		SUITE 550
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_162646291750227.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-07-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000709283</issuerCik>
        <issuerName>QUANTUM CORP /DE/</issuerName>
        <issuerTradingSymbol>QMCO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001602567</rptOwnerCik>
            <rptOwnerName>Lerner James J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O QUANTUM CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>224 AIRPORT PARKWAY, SUITE 550</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-07-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>65560</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.3974</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1677358</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the number of shares automatically sold, on a non-discretionary basis, to cover tax withholding obligations in connection with the vesting of restricted stock units and performance-based stock units granted on July 1, 2020.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Josie Buensuceso, Attorney-in-Fact for James J. Lerner</signatureName>
        <signatureDate>2021-07-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
