<SEC-DOCUMENT>0001101302-25-000087.txt : 20250821
<SEC-HEADER>0001101302-25-000087.hdr.sgml : 20250821
<ACCEPTANCE-DATETIME>20250821162458
ACCESSION NUMBER:		0001101302-25-000087
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250821
FILED AS OF DATE:		20250821
DATE AS OF CHANGE:		20250821

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Reeder David
		CENTRAL INDEX KEY:			0001597133
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32598
		FILM NUMBER:		251241172

	MAIL ADDRESS:	
		STREET 1:		129 CONCORD ROAD
		CITY:			BILLERICA
		STATE:			MA
		ZIP:			01821

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ENTEGRIS INC
		CENTRAL INDEX KEY:			0001101302
		STANDARD INDUSTRIAL CLASSIFICATION:	PLASTICS PRODUCTS, NEC [3089]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		EIN:				411941551
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		129 CONCORD ROAD
		CITY:			BILLERICA
		STATE:			MA
		ZIP:			01821
		BUSINESS PHONE:		9784366500

	MAIL ADDRESS:	
		STREET 1:		129 CONCORD ROAD
		CITY:			BILLERICA
		STATE:			MA
		ZIP:			01821
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1755807895.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-08-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001101302</issuerCik>
        <issuerName>ENTEGRIS INC</issuerName>
        <issuerTradingSymbol>ENTG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001597133</rptOwnerCik>
            <rptOwnerName>Reeder David</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ENTEGRIS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>129 CONCORD ROAD</rptOwnerStreet2>
            <rptOwnerCity>BILLERICA</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01821</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-08-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2897</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>58457</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents restricted stock units granted to Mr. Reeder on April 23, 2025 in consideration for his services as an independent director.  These restricted stock units, which are unvested, are being forfeited in conjunction with the awards granted to Mr. Reeder on August 18, 2025 in consideration for his new role as the Company's President and CEO.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Joseph Colella, Attorney-In-Fact for David Reeder</signatureName>
        <signatureDate>2025-08-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
