Form S-8 POS INNIO N.V.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

POST-EFFECTIVE AMENDMENT NO. 1 TO

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

INNIO N.V.

(Exact name of registrant as specified in its charter)

(Address, including zip code of Principal Executive Offices)

2026 Incentive Award Plan

(Full title of the plan)

INNIO Holding Inc.

Authorized U.S. Representative

1101 W. St. Paul Ave.

Waukesha, WI 53188

+1.262.547.3311

(Name, address and telephone number, including area code, of agent for service)

Copy to:

Marc D. Jaffe

Ian D. Schuman

Oliver Seiler

Jennifer M. Gascoyne

Latham & Watkins LLP

1271 Avenue of the Americas

New York, NY 10020

(212) 906-1200

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 of 1934, as amended (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

This Post-Effective Amendment No. 1 (this “Post-Effective Amendment”) to the Registration Statement on Form S-8 (Registration No. 333-296562) (the “Original Filing”) filed by INNIO N.V. (the “Registrant”) with the Securities and Exchange Commission (the “Commission”) on June 5, 2026 is being filed solely to correct a clerical error appearing on the signature page of the authorized representative. Except as described herein, this Post-Effective Amendment does not update, amend or modify any other information, statement or disclosure contained in the Original Filing.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 8. Exhibits.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant 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 Post-Effective Amendment to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Munich, Federal Republic of Germany, on this 5th day of August, 2026.

Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment has been signed by the following persons in the capacities indicated on August 5, 2026.

SIGNATURE OF AUTHORIZED U.S. REPRESENTATIVE OF THE REGISTRANT

Pursuant to the requirements of the Securities Act, the undersigned certifies that it is the duly authorized United States representative of the registrant and has duly caused this Post-Effective Amendment to be signed by the undersigned, thereunto duly authorized, in the City of Waukesha, Wisconsin, on August 5, 2026.