<SEC-DOCUMENT>0001628280-16-018834.txt : 20160809
<SEC-HEADER>0001628280-16-018834.hdr.sgml : 20160809
<ACCEPTANCE-DATETIME>20160809191222
ACCESSION NUMBER:		0001628280-16-018834
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160806
FILED AS OF DATE:		20160809
DATE AS OF CHANGE:		20160809

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KLA TENCOR CORP
		CENTRAL INDEX KEY:			0000319201
		STANDARD INDUSTRIAL CLASSIFICATION:	OPTICAL INSTRUMENTS & LENSES [3827]
		IRS NUMBER:				042564110
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		ONE TECHNOLOGY DRIVE
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035
		BUSINESS PHONE:		4088756000

	MAIL ADDRESS:	
		STREET 1:		ONE TECHNOLOGY DRIVE
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KLA INSTRUMENTS CORP
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WALLACE RICHARD P
		CENTRAL INDEX KEY:			0001196898

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-09992
		FILM NUMBER:		161819642

	MAIL ADDRESS:	
		STREET 1:		KLA TENCOR
		STREET 2:		160 RIO ROBLES
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_147078432902128.xml
<DESCRIPTION>FORM 4
<TEXT>
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    <periodOfReport>2016-08-06</periodOfReport>

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    <issuer>
        <issuerCik>0000319201</issuerCik>
        <issuerName>KLA TENCOR CORP</issuerName>
        <issuerTradingSymbol>KLAC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001196898</rptOwnerCik>
            <rptOwnerName>WALLACE RICHARD P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O KLA-TENCOR CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>ONE TECHNOLOGY DRIVE</rptOwnerStreet2>
            <rptOwnerCity>MILPITAS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95035</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

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            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
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                <transactionCode>M</transactionCode>
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                <value>Common Stock</value>
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                <value>2016-08-07</value>
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                <transactionCode>F</transactionCode>
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                    <value>5740</value>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
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                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9182</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock - Restricted Stock Units</value>
                <footnoteId id="F8"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>155537</value>
                    <footnoteId id="F9"/>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On August 6, 2013, the Reporting Person received a grant of restricted stock units (&quot;RSUs&quot;) covering 44,500 shares of KLA-Tencor common stock.  On August 6, 2016, the Reporting Person vested in twenty-five percent (25%) of such RSUs.</footnote>
        <footnote id="F2">Pursuant to such terms of the August 6, 2013 RSU grant, 5,806 shares of KLA-Tencor common stock were automatically withheld at vesting to cover required tax withholding.  Because the vesting date of such RSUs occurred on a day on which the NASDAQ Stock Market was closed for trading, the fair market value of KLA-Tencor common stock used for purposes of calculating the number of shares to be withheld was the closing price of KLA-Tencor common stock as reported on the last completed trading day immediately prior to such vesting date.</footnote>
        <footnote id="F3">On August 6, 2015, the Reporting Person received a grant of RSUs covering 52,950 shares of KLA-Tencor common stock.  On August 6, 2016, the Reporting Person vested in twenty-five percent (25%) of such RSUs.</footnote>
        <footnote id="F4">Pursuant to such terms of the August 6, 2014 RSU grant, 6,908 shares of KLA-Tencor common stock were automatically withheld at vesting to cover required tax withholding.  Because the vesting date of such RSUs occurred on a day on which the NASDAQ Stock Market was closed for trading, the fair market value of KLA-Tencor common stock used for purposes of calculating the number of shares to be withheld was the closing price of KLA-Tencor common stock as reported on the last completed trading day immediately prior to such vesting date.</footnote>
        <footnote id="F5">On August 7, 2014, the Reporting Person received a grant of RSUs covering 44,000 shares of KLA-Tencor common stock.  On August 7, 2016, the Reporting Person vested in twenty-five percent (25%) of such RSUs.</footnote>
        <footnote id="F6">Pursuant to such terms of the August 7, 2014 RSU grant, 5,740 shares of KLA-Tencor common stock were automatically withheld at vesting to cover required tax withholding.  Because the vesting date of such RSUs occurred on a day on which the NASDAQ Stock Market was closed for trading, the fair market value of KLA-Tencor common stock used for purposes of calculating the number of shares to be withheld was the closing price of KLA-Tencor common stock as reported on the last completed trading day immediately prior to such vesting date.</footnote>
        <footnote id="F7">Shares held under the Wallace Living Trust u/a/d 03/27/01, as amended, a trust of which the Reporting Person is a trustee and beneficiary.</footnote>
        <footnote id="F8">Each RSU represents a contingent right to receive one share of KLA-Tencor common stock.</footnote>
        <footnote id="F9">Does not include performance-based RSUs, if any, held by the Reporting Person for which an assessment has not yet been made regarding the achievement of the applicable performance goals.  Any such holdings will be reported on a Form 4 within two business days of the date such assessment is made.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Teri Little as Attorney-in-Fact for Richard P. Wallace</signatureName>
        <signatureDate>2016-08-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
