<SEC-DOCUMENT>0001643526-18-000010.txt : 20180511
<SEC-HEADER>0001643526-18-000010.hdr.sgml : 20180511
<ACCEPTANCE-DATETIME>20180511154229
ACCESSION NUMBER:		0001643526-18-000010
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180509
FILED AS OF DATE:		20180511
DATE AS OF CHANGE:		20180511

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RENZI JEFFREY
		CENTRAL INDEX KEY:			0001249949

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08729
		FILM NUMBER:		18826692

	MAIL ADDRESS:	
		STREET 1:		UNISYS CORPORATION
		STREET 2:		108 LAKEVIEW DRIVE, SUITE 100
		CITY:			BLUE BELL
		STATE:			PA
		ZIP:			19422

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			UNISYS CORP
		CENTRAL INDEX KEY:			0000746838
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER INTEGRATED SYSTEMS DESIGN [7373]
		IRS NUMBER:				380387840
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		801 LAKEVIEW DRIVE, SUITE 100
		CITY:			BLUE BELL
		STATE:			PA
		ZIP:			19422
		BUSINESS PHONE:		2159864011

	MAIL ADDRESS:	
		STREET 1:		801 LAKEVIEW DRIVE, SUITE 100
		CITY:			BLUE BELL
		STATE:			PA
		ZIP:			19422

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BURROUGHS CORP /DE/
		DATE OF NAME CHANGE:	19861204
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-05-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000746838</issuerCik>
        <issuerName>UNISYS CORP</issuerName>
        <issuerTradingSymbol>UIS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001249949</rptOwnerCik>
            <rptOwnerName>RENZI JEFFREY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>UNISYS CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>108 LAKEVIEW DRIVE, SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>BLUE BELL</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19422</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-05-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.9609</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>52304</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in column 4 is a weighted average price.  These shares were sold in multiple transactions at prices ranging from $11.931 to $11.981, inclusive.  The reporting person undertakes to provide Unisys Corporation, any security holder of Unisys Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (1) to this Form 4.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>John M. Armbruster, attorney-in-fact</signatureName>
        <signatureDate>2018-05-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
