SEC Form S-8 filed by Ultra Clean Holdings Inc.

As filed with the Securities and Exchange Commission on July 10, 2026

Registration No. 333-

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM S-8
REGISTRATION STATEMENT UNDER
THE SECURITIES ACT OF 1933

ULTRA CLEAN HOLDINGS, INC.
(Exact Name of Registrant as Specified in its Charter)

Ultra Clean Holdings, Inc. Amended and Restated Stock Incentive Plan
Ultra Clean Holdings, Inc. Amended and Restated Employee Stock Purchase Plan
(Full Titles of the Plans)

James Xiao
Chief Executive Officer
Ultra Clean Holdings, Inc.
26462 Corporate Avenue
Hayward, CA 94545
(510) 576-4600 (Name, Address, Including Zip Code, and
Telephone Number, Including Area Code, of Agent For Service)

With copies to:

Alan F. Denenberg
Jason Bassetti
Davis Polk & Wardwell LLP
900 Middlefield Road
Redwood City, California 94063
(650) 752-2000

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer, ” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.  

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

EXPLANATORY NOTE

Pursuant to General Instruction E to Form S-8, Ultra Clean Holdings, Inc. (the “Registrant”) is filing this Registration Statement on Form S-8 (this “Registration Statement”) with the U.S. Securities and Exchange Commission (the “Commission”) to register an additional 3,500,000 shares of common stock of the Registrant for issuance under the Registrant’s Amended and Restated Stock Incentive Plan (the “Stock Plan”) and 450,000 shares of common stock of the Registrant for issuance under the Registrant’s Employee Stock Purchase Plan (“ESPP”). These additional shares of common stock are securities of the same class and relate to the same employee benefit plan (as amended from time to time) as other securities for which a registration statement on Form S-8 has been filed with the Securities and Exchange Commission on March 30, 2004 (File No. 333-114051), April 4, 2005 (File No. 333-123820), June 19, 2006 (File No. 333-135147), April 9, 2007 (File No. 333-141989), May 30, 2008 (File No. 333-151335), March 19, 2009 (File No. 333-158108), March 30, 2010 (File No. 333-165782), June 15, 2010 (File No. 333-167530), May 31, 2013 (File No. 333-188995), July 25, 2017 (File No. 333-219447), December 18, 2019 (File No. 333-235574) and March 20, 2024 (File No. 333-278114), the contents of which are hereby incorporated by reference. These additional shares of common stock have become reserved for issuance as a result of the amendment and restatement of (i) the Registrant’s Amended and Restated Stock Incentive Plan, effective as of May 22, 2026 and (ii) the Registrant’s Amended and Restated Employee Stock Purchase Plan, effective as of May 22, 2026.

PART II
INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

The following documents filed by the Registrant with the Commission under the Securities Act of 1933, as amended (the “Securities Act”) or the Securities Exchange Act of 1934, as amended (the “Exchange Act”), are incorporated herein by reference:

In addition, all documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act (other than documents or any information therein deemed to have been furnished and not filed in accordance with rules of the Commission), prior to the filing of a post-effective amendment to this Registration Statement, which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference in this Registration Statement and to be a part hereof from the date of the filing of such documents.

Any statement contained in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this Registration Statement to the extent that a statement contained herein (or in any other subsequently filed document which also is incorporated or deemed to be incorporated by reference herein), modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Registration Statement.

Item 8.  Exhibits.

*       Filed herewith.

SIGNATURES

Pursuant to the requirements of the Securities Act, the Registrant, Ultra Clean Holdings, Inc., certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Hayward, State of California, on the 10^th day of July, 2026.

POWER OF ATTORNEY AND SIGNATURES

Know all persons by these presents, that each person whose signature appears below constitutes and appoints James Xiao and Sheri Savage and each of them, as his or her true and lawful attorney-in-fact and agents, upon the action of such appointee, with full power of substitution and resubstitution, to do any and all acts and things and execute, in the name of the undersigned, any and all instruments which each of said attorneys-in-fact and agents may deem necessary or advisable in order to enable Ultra Clean Holdings, Inc, to comply with the Securities Act, and any requirements of the Commission in respect thereof, in connection with the filing with the Commission of this Registration Statement under the Securities Act, including specifically but without limitation, power and authority to sign the name of the undersigned to such Registration Statement, and any amendments to such Registration Statement (including post-effective amendments), and to file the same with all exhibits thereto and other documents in connection therewith, with the Commission, to sign any and all applications, registration statements, notices or other documents necessary or advisable to comply with applicable state securities laws, and to file the same, together with other documents in connection therewith with the appropriate state securities authorities, granting unto each of said attorneys-in-fact and agents full power and authority to do and to perform each and every act and thing requisite or necessary to be done in and about the premises, as fully and to all intents and purposes as the undersigned might or could do in person, hereby ratifying and confirming all that each of said attorneys-in-fact and agents may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated: