As filed with the Securities and Exchange Commission on June 5, 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

INNIO N.V.

(Exact name of registrant as specified in its charter)

Nymphenburger Strasse 5

80335 Munich, Germany

+49.89.89.82.7221

(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. ☐

PART I

INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1. Plan Information.

Not required to be filed with this Registration Statement.

Item 2. Registrant Information and Employee Plan Annual Information.

Not required to be filed with this Registration Statement.

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

The following documents filed or to be filed (other than portions of those documents furnished or otherwise not deemed filed) by the Company with the Securities and Exchange Commission (the “Commission”) are incorporated into this Registration Statement by reference, as of their respective dates:

All documents subsequently filed by the Company pursuant to Sections 13(a), 13(c), 14, and 15(d) of the Exchange Act subsequent to the date of this Registration Statement and prior to the filing of a post-effective amendment to this Registration Statement which indicates that all securities then remaining unsold shall be deregistered, shall be deemed to be incorporated by reference in the Registration Statement and to be a part thereof from the date of the filing of such documents.

For purposes of this Registration Statement and the related prospectus, any statement contained in a document incorporated or deemed to be incorporated by reference shall be deemed to be modified or superseded to the extent that a statement contained herein or in a subsequently filed document which also is or is deemed to be incorporated herein by reference modifies or replaces such statement. Any statement so modified shall not be deemed in its unmodified form to constitute part of this Registration Statement or the related prospectus.

Item 4. Description of Securities.

Not applicable.

Item 5. Interests of Named Experts and Counsel.

Not applicable.

Item 6. Indemnification of Directors and Officers.

Under Dutch law, our directors may be held liable for damages in the event of improper or negligent performance of their duties. They may be held liable for damages to our company and to third parties for infringement of our articles

of association or of certain provisions of Dutch law. In certain circumstances, they may also incur other specific civil and criminal liabilities. Subject to certain exceptions, our articles of association provide for indemnification of our current and former directors and other current and former officers and employees as designated by our board of directors. No indemnification under our articles of association shall be given to an indemnified person: (a) if a competent court or arbitral tribunal has established, without having (or no longer having) the possibility for appeal, that the acts or omissions of such indemnified person that led to the financial losses, damages, expenses, suit, claim, action or legal proceedings as described above are of an unlawful nature (including acts or omissions which are considered to constitute malice, gross negligence, intentional recklessness and/or serious culpability attributable to such indemnified person); (b) to the extent that his or her financial losses, damages and expenses are covered under insurance and the relevant insurer has settled, or has provided reimbursement for, these financial losses, damages and expenses (or has irrevocably undertaken to do so); (c) in relation to proceedings brought by such indemnified person against our company, except for proceedings brought to enforce indemnification to which he or she is entitled pursuant to our articles of association, pursuant to an agreement between such indemnified person and our company which has been approved by our board of directors or pursuant to insurance taken out by our company for the benefit of such indemnified person; and (d) for any financial losses, damages or expenses incurred in connection with a settlement of any proceedings effected without our prior consent.

Under our articles of association, our board of directors may stipulate additional terms, conditions and restrictions in relation to the indemnification described above. Reference is also made to the underwriting agreement, a form of which was filed with the Form S-1 for the Company’s initial public offering, which provides for the indemnification of officers, directors and controlling persons of the Company, within the meaning of the Securities Act against certain liabilities.

See also the Undertakings set forth in the response to Item 9 herein.

Item 7. Exemption from Registration Claimed.

Not applicable.

Item 8. Exhibits.

Item 9. Undertakings.

A. The Company hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective Registration Statement;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the Registration Statement or any material change to such information in the Registration Statement;

Provided, however, that paragraphs (A)(1)(i) and (A)(1)(ii) do not apply if the Registration Statement is on Form S-8, and the information required to be included in the post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the Commission by the Company pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in this Registration Statement.

(2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new Registration Statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

B. The undersigned Company hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the Company’s annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new Registration Statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

C. Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Company pursuant to the foregoing provisions, or otherwise, the Company has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Company of expenses incurred or paid by a director, officer or controlling person of the Company in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Company will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question of whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

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 Registration Statement 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 June, 2026.

POWER OF ATTORNEY

KNOW ALL MEN AND WOMEN BY THESE PRESENTS, that each person whose signature appears below hereby severally constitutes and appoints each of the Company’s Chief Executive Officer and Chief Financial Officer (currently Dr. Olaf Berlien and Dr. Dennis Schulze, respectively) as such person’s true and lawful attorney-in-fact and agent, each acting alone, with full power of substitution and resubstitution, for and in such person’s name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement and all documents relating thereto, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Commission, granting unto such attorneys-in-fact and agents, each acting alone, full power and authority to do and perform each and every act and thing necessary or advisable to be done in and about the premises, as fully to all intents and purposes as such person might or could do in person, hereby ratifying and confirming all that such attorneys-in-fact and agents, each acting alone, or such person’s substitute or substitutes, lawfully may do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities indicated on June 5, 2026.

To the Company:

We have acted as legal counsel as to Dutch law to the Company in connection with the Plan and the filing of the Registration Statement with the SEC. This opinion letter is rendered to you in order to be filed with the SEC as an exhibit to the Registration Statement.

Capitalised terms used in this opinion letter have the meanings set forth in Exhibit A to this opinion letter. The headings used in this opinion letter are for convenience of reference only and are not to affect its construction or to be taken into consideration in its interpretation.

This opinion letter is strictly limited to the matters stated in it and may not be read as extending by implication to any matters not specifically referred to in it. Nothing in this opinion letter should be taken as expressing an opinion in respect of any representations or warranties, or other information, contained in any document reviewed by us in connection with this opinion letter.

In rendering the opinions expressed in this opinion letter, we have reviewed and relied upon a draft of the Registration Statement and pdf copies of the Plan and the Corporate Documents and we have assumed that Awards under the Plan shall be made for bona fide commercial reasons. We have not investigated or verified any factual matter disclosed to us in the course of our review.

This opinion letter sets out our opinion on certain matters of the laws with general applicability of the Netherlands, and, insofar as they are directly applicable in the Netherlands, of the European Union, as at today's date and as presently interpreted under published authoritative case law of the Dutch courts, the General Court and the Court of Justice of the European Union. We do not express any opinion on Dutch or European competition law, data protection law, tax law, securitisation law or regulatory law. No undertaking is assumed on our part to revise, update or amend this opinion letter in connection with, or to notify or inform you of, any developments and/or changes of Dutch law subsequent to today's date. We do not purport to opine on the consequences of amendments to the Plan, the Registration Statement or the Corporate Documents subsequent to the date of this opinion letter.

The opinions expressed in this opinion letter are to be construed and interpreted in accordance with Dutch law. The competent courts at Amsterdam, the Netherlands, have exclusive jurisdiction to settle any issues of interpretation or liability arising out of or in connection with this opinion letter. Any legal relationship arising out of or in connection with this opinion letter (whether contractual or non-contractual), including the above submission to jurisdiction, is governed by Dutch law and shall be subject to the general terms and conditions of NautaDutilh. Any liability arising out of or in connection with this opinion letter shall be limited to the amount which is paid out under NautaDutilh's insurance policy in the matter concerned. No person other than NautaDutilh may be held liable in connection with this opinion letter.

In this opinion letter, legal concepts are expressed in English terms. The Dutch legal concepts concerned may not be identical in meaning to the concepts described by the English terms as they exist under the law of other jurisdictions. In the event of a conflict or inconsistency, the relevant expression shall be deemed to refer only to the Dutch legal concepts described by the English terms.

For the purposes of this opinion letter, we have assumed that:

Based upon and subject to the foregoing and subject to the qualifications set forth in this opinion letter and to any matters, documents or events not disclosed to us, we express the following opinions:

Cross-Border Conversion and Corporate Status

Plan Shares

The opinions expressed above are subject to the following qualifications:

We consent to the filing of this opinion letter as an exhibit to the Registration Statement. In giving this consent we do not admit or imply that we are a person whose consent is required under Section 7 of the United States Securities Act of 1933, as amended, or any rules and regulations promulgated thereunder.

Sincerely yours,

/s/ NautaDutilh N.V.

NautaDutilh N.V.

EXHIBIT A

LIST OF DEFINITIONS

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the use of our report dated March 26, 2026, with respect to the consolidated financial statements of INNIO Holding GmbH, incorporated herein by reference.

/s/ KPMG AG Wirtschaftsprüfungsgesellschaft

Stuttgart, Germany

June 5, 2026