<SEC-DOCUMENT>0001280263-25-000040.txt : 20250904
<SEC-HEADER>0001280263-25-000040.hdr.sgml : 20250904
<ACCEPTANCE-DATETIME>20250904184431
ACCESSION NUMBER:		0001280263-25-000040
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250902
FILED AS OF DATE:		20250904
DATE AS OF CHANGE:		20250904

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hu Chenming
		CENTRAL INDEX KEY:			0001316320
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35667
		FILM NUMBER:		251294612

	MAIL ADDRESS:	
		STREET 1:		2060 PEBBLE DRIVE
		CITY:			ALAMO
		STATE:			CA
		ZIP:			94507

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMBARELLA INC
		CENTRAL INDEX KEY:			0001280263
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		ORGANIZATION NAME:           	04 Manufacturing
		EIN:				980459628
		FISCAL YEAR END:			0131

	BUSINESS ADDRESS:	
		STREET 1:		3001 TASMAN DRIVE
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054
		BUSINESS PHONE:		408-734-8888

	MAIL ADDRESS:	
		STREET 1:		3001 TASMAN DRIVE
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-09-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001280263</issuerCik>
        <issuerName>AMBARELLA INC</issuerName>
        <issuerTradingSymbol>AMBA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001316320</rptOwnerCik>
            <rptOwnerName>Hu Chenming</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3001 TASMAN DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2025-09-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2498</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29516</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Effective as of September 2, 2025, the Board of Directors approved an annual restricted stock unit grant of 2,498 Ordinary Shares to each independent director. The RSU grant vests as to 1/4th of the Ordinary Shares each three months following the vesting start date of September 15, 2025, so as to be 100% vested on September 15, 2026, subject to continued service with the Company.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: /s/ Michael Morehead, Attorney-in-Fact For: Chenming Hu</signatureName>
        <signatureDate>2025-09-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
