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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 Ul6v/sH3H2i73Yt+4kyhTw==

<SEC-DOCUMENT>0001179110-06-005006.txt : 20060228
<SEC-HEADER>0001179110-06-005006.hdr.sgml : 20060228
<ACCEPTANCE-DATETIME>20060228160056
ACCESSION NUMBER:		0001179110-06-005006
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20051231
FILED AS OF DATE:		20060228
DATE AS OF CHANGE:		20060228

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CRAY INC
		CENTRAL INDEX KEY:			0000949158
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRONIC COMPUTERS [3571]
		IRS NUMBER:				930962605
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		411 FIRST AVE SOUTH
		STREET 2:		SUITE 600
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98104-2860
		BUSINESS PHONE:		2067012000

	MAIL ADDRESS:	
		STREET 1:		411 FIRST AVE SOUTH
		STREET 2:		SUITE 600
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98104-2860

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TERA COMPUTER CO \WA\
		DATE OF NAME CHANGE:	19950809

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WILLIAMS MARGARET ANN
		CENTRAL INDEX KEY:			0001325486

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26820
		FILM NUMBER:		06650989

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		206-701-2000

	MAIL ADDRESS:	
		STREET 1:		411 FIRST AVENUE SOUTH, SUITE 600
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98104
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 5 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2005-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000949158</issuerCik>
        <issuerName>CRAY INC</issuerName>
        <issuerTradingSymbol>CRAY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001325486</rptOwnerCik>
            <rptOwnerName>WILLIAMS MARGARET ANN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>411 FIRST AVENUE S., SUITE 600</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SEATTLE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98104</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SENIOR VICE PRESIDENT</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>350000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2005-09-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3170</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.0250</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>353170</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2005-12-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3401</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>.8670</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>356571</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Acquired under issuer's Employee Stock Purchase Plan.  These transactions are exempt from the reporting requirements under Section 16(a) pursuant to Rule 16-a3(f)(1)(i)(B).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Margaret Ann Williams by Kenneth W. Johnson, Attorney-in-Fact</signatureName>
        <signatureDate>2006-02-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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