<SEC-DOCUMENT>0001628280-18-001608.txt : 20180213
<SEC-HEADER>0001628280-18-001608.hdr.sgml : 20180213
<ACCEPTANCE-DATETIME>20180213190852
ACCESSION NUMBER:		0001628280-18-001608
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20171230
FILED AS OF DATE:		20180213
DATE AS OF CHANGE:		20180213

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lerner Eric
		CENTRAL INDEX KEY:			0001549062

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13792
		FILM NUMBER:		18606061

	MAIL ADDRESS:	
		STREET 1:		C/O SYSTEMAX INC.
		CITY:			11 HARBOR PARK DRIVE
		STATE:			NY
		ZIP:			11050

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SYSTEMAX INC
		CENTRAL INDEX KEY:			0000945114
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-CATALOG & MAIL-ORDER HOUSES [5961]
		IRS NUMBER:				113262067
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		11 HARBOR PARK DR
		CITY:			PORT WASHINGTON
		STATE:			NY
		ZIP:			11050
		BUSINESS PHONE:		5166087000

	MAIL ADDRESS:	
		STREET 1:		11 HARBOR PARK DRIVE
		CITY:			PORT WASHINGTON
		STATE:			NY
		ZIP:			11050

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GLOBAL DIRECTMAIL CORP
		DATE OF NAME CHANGE:	19950509
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>wf-form5_151856691672222.xml
<DESCRIPTION>FORM 5
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2017-12-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000945114</issuerCik>
        <issuerName>SYSTEMAX INC</issuerName>
        <issuerTradingSymbol>SYX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001549062</rptOwnerCik>
            <rptOwnerName>Lerner Eric</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SYSTEMAX INC.</rptOwnerStreet1>
            <rptOwnerStreet2>11 HARBOR PARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>PORT WASHINGTON</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11050</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior VP &amp; General Counsel</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-02-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3523</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.47</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21477</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares surrendered to the Issuer for payment of tax liability incident to vesting of prior restricted stock award.</footnote>
        <footnote id="F2">The amount of non-derivative securities beneficially owned at the end of Issuer's fiscal year is 21,477, which includes the February 1, 2016 grant of 25,000 Restricted Stock Units (16,666 remain unvested) and 4,811 shares of common stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Eric Lerner by April Gruder, Attorney-in-Fact</signatureName>
        <signatureDate>2018-02-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
