    <SEC-DOCUMENT>0000950170-25-052320-index.html : 20250409
    <SEC-HEADER>0000950170-25-052320.hdr.sgml : 20250409
    <ACCEPTANCE-DATETIME>20250409085518
    ACCESSION NUMBER:		0000950170-25-052320
    CONFORMED SUBMISSION TYPE:	DEFA14A
    PUBLIC DOCUMENT COUNT:		3
    FILED AS OF DATE:		20250409
    DATE AS OF CHANGE:		20250409

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			ONTO INNOVATION INC.
    		CENTRAL INDEX KEY:			0000704532
    		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
    		ORGANIZATION NAME:           	08 Industrial Applications and Services
    		EIN:				942276314
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1226

    	FILING VALUES:
    		FORM TYPE:		DEFA14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-39110
    		FILM NUMBER:		25823935

    	BUSINESS ADDRESS:
    		STREET 1:		16 JONSPIN ROAD
    		CITY:			WILMINGTON
    		STATE:			MA
    		ZIP:			01887
    		BUSINESS PHONE:		9782536200

    	MAIL ADDRESS:
    		STREET 1:		16 JONSPIN ROAD
    		CITY:			WILMINGTON
    		STATE:			MA
    		ZIP:			01887

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	Onto Innovation Inc.
    		DATE OF NAME CHANGE:	20191025

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	NANOMETRICS INC
    		DATE OF NAME CHANGE:	19920703
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEFA14A
    <SEQUENCE>1
    <FILENAME>onto_defa14a_2025.htm
    <DESCRIPTION>DEFA14A
    <TEXT>
    Document 1 - file: onto_defa14a_2025.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>2
    <FILENAME>img235976323_0.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: img235976323_0.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>img235976323_1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 3 - file: img235976323_1.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>