Orion S.A.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934 (Amendment No. )

Orion S.A.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

**Orion S.A.

Société Anonyme

6, Route de Trèves

L-2633 Senningerberg (Municipality of Niederanven)

Grand Duchy of Luxembourg

Notice of 2026 Annual General Meeting of Shareholders

The Annual General Meeting of Shareholders will be held through private deed and convene on

Thursday, June 25, 2026, at 2:00 p.m. CET, at the registered office of the Company at:

**6, Route de Trèves

L-2633 Senningerberg (Municipality of Niederanven)

Grand Duchy of Luxembourg

Dear Shareholders of Orion S.A.,

The board of directors (the “Board of Directors” or “Board”) of Orion S.A., a société anonyme having its registered office at 6, Route de Trèves, L-2633 Senningerberg (Municipality of Niederanven), Grand Duchy of Luxembourg, registered with the Luxembourg Trade and Companies Register under registration number B 160558 (the “Company” or “Orion”), convened, in accordance with the provisions of article 10 of the articles of association of the Company, an Annual General Meeting of Shareholders (the “Annual General Meeting” or “General Meeting”). You are cordially invited to attend our 2026 Annual General Meeting of Shareholders, which will be held at the Company’s headquarters at 6, Route de Trèves, L-2633 Senningerberg (Municipality of Niederanven), Grand Duchy of Luxembourg at 2:00 p.m. Central European Time (“CET”) on June 25, 2026.

A Notice of Internet Availability of Proxy Materials for the 2026 Annual General Meeting of Shareholders will be mailed to shareholders on or around May 15, 2026.

The following is the agenda of the Annual General Meeting:

Procedures for Voting and Attendance for the General Meeting

The Company urges each shareholder to cast their vote at the General Meeting by completing, signing, dating and returning the respective proxy made available by the Company for use at the General Meeting in accordance with the instructions below.

Only holders of record of the Company’s common shares (the “Common Shares”) outstanding on April 23, 2026, at 11:59 P.M. CET (the “Record Date”) are entitled to attend and vote at the General Meeting.

As of April 23, 2026, the Company had 56,388,649 Common Shares issued and outstanding. Each shareholder is entitled to one vote for each Common Share held of record by such shareholder as of the Record Date, on each matter submitted to a vote at the General Meeting. All Common Shares represented by proxy for the General Meeting duly executed and received by voting via telephone or internet until June 18, 2026, 11:59 P.M. EST (June 19, 2026 5:59 A.M. CET), and by voting via hard copy ballots until June 19, 2026, 12:00 P.M. (noon) EST (June 19, 2026 6:00 P.M. CET) (the “Voter Deadline”) will be voted at the General Meeting in accordance with the terms of the proxy. If any other item is properly added to the agenda for the General Meeting under the Company’s articles of association or Luxembourg law, proxies for such General Meeting will be voted in accordance with the best judgment of the proxyholders. Generally, only the items appearing in the convening notice and agenda for the General Meeting can be voted on at the General Meeting. Each shareholder can vote only once on each item on the agenda of the General Meeting. A shareholder may revoke a proxy for the General Meeting by (i) submitting a document revoking it prior to the Voter Deadline, (ii) submitting a duly executed proxy bearing a later date prior to the Voter Deadline, or (iii) attending the General Meeting and voting in person.

You may cast your vote at the General Meeting by marking, signing and dating the proxy card for the General Meeting and returning the proxy card in the enclosed envelope (postage within the United States paid; or in another envelope, postage to be paid), to: Equiniti Trust Company LLC, PO Box 52449, Newark, NJ, 07101 - 9916, U.S.A. Proxy cards that are mailed must be received by Equiniti Trust Company LLC at the above address by the Voter Deadline. No postage is required for mailing of the enclosed envelope in the United States. The Company will bear the cost of soliciting proxies with respect to the matters to be voted on at the General Meeting.

Alternatively, you may also cast your vote over the Internet, atwww.proxyvote.com (beneficial shareholders) orwww.voteproxy.com (registered shareholders), or by telephone, by following the instructions on your proxy card or the instructions that you received by e-mail from the Company, if you opted for electronic delivery. If you plan to vote over the Internet or by telephone, your votes must be received no later than the Voter Deadline to allow sufficient time to tabulate the votes prior to the start of the General Meeting.

Shareholders may also vote in person at the General Meeting. To vote at the meeting, shareholders must present valid government- issued photo identification. If your shares are held by a bank or broker or other agent, you must also obtain and present a “legal proxy” from the holder of record to vote at the General Meeting. For specific instructions, please refer to the proxy card, notice or e-mail notification you received. Admittance of shareholders to the General Meeting and acceptance of written voting proxies will be governed by Luxembourg law.

Even if you plan to attend the General Meeting, we recommend that you vote your shares in advance of the General Meeting in one of the manners available to you so that your vote will be counted if you later are unable to attend the General Meeting.

If you hold your Common Shares through a bank, brokerage firm or other agent and do not give instructions to your bank, brokerage firm or other agent as to how your Common Shares should be voted at the General Meeting, the Common Shares that you hold through a bank, brokerage firm or other agent will not be voted at the General Meeting on Proposals 1 through 9.

The Company therefore urges all shareholders who hold their Common Shares through a bank, brokerage firm or other agent to promptly provide voting instructions in accordance with the procedures of their bank, brokerage firm or other agent. Your ability to vote over the Internet or by telephone depends on the voting procedures of your bank or broker or other agent.

Directors, executive officers and employees of the Company may solicit proxies in person or by mail, telephone or e-mail, but will not receive any additional compensation for these services. The Company may reimburse brokers and others for their reasonable expenses in forwarding proxy solicitation material to the beneficial owners of Common Shares. The Company may retain a proxy solicitation firm to assist in the solicitation of proxies for the General Meeting.

Each shareholder of record who holds one or more Common Shares on the Record Date will be admitted to participate and vote in the General Meeting. A holder of Common Shares held through an operator of a securities settlement system or recorded as book-entry interests in the accounts of a professional depositary who wishes to attend the General Meeting should receive from such operator or depositary a certificate certifying (i) the number of Common Shares recorded in the relevant account on the Record Date and (ii) that such Common Shares are blocked until the closing of the General Meeting. The certificate should be submitted to the Company no later than the Voter Deadline. If you plan to attend the General Meeting, you are kindly requested to notify the Company thereof in writing and provide your name, address and telephone number and any other necessary materials before the Voter Deadline by post to the registered office of the Company located at 6, Route de Trèves, L-2633 Senningerberg (Municipality of Niederanven), Grand Duchy of Luxembourg, or by e-mail toinvestor-relations@orioncarbons.com.

The General Meeting will also be held by live webcast, in addition to the physical location, at 2:00 p.m. CET on June 25, 2026. The dial-in information for participation in the General Meeting by live webcast will be published on our website athttps://investor.orioncarbons.com/governance/Proxy-Statements/default.aspx one week prior to the date of the General Meeting. You may ask questions to the Board of Directors until 11:59 p.m. CET on June 22, 2026 by sending an e-mail toinvestor-relations@orioncarbons.com together with a proof of shareholding. The Board of Directors will respond at the General Meeting to questions duly submitted by shareholders. It will not be possible to raise questions and vote shares during the meeting if you participate via teleconference, and we encourage you therefore to vote your Common Shares prior to the General Meeting.

Shareholders are not entitled to preemptive rights or cumulative voting on any of the aforementioned proposals, nor are holders entitled to appraisal or dissenters’ rights for any matter being voted on at the General Meeting.

Right to Add Items to the Agenda of the General Meeting and to Table Draft Resolutions

One or more shareholders of record holding at least 10% of the outstanding Common Shares (excluding, for the avoidance of doubt, any Common Shares repurchased by the Company) may add items to the agenda of the General Meeting, provided that each such item is accompanied by a justification or a draft resolution to be adopted in the General Meeting. If you plan to add items to the agenda of the General Meeting, you must notify the Company thereof in writing and provide your name, address and telephone number by registered mail to the registered office the Company located at 6, Route de Trèves, L-2633 Senningerberg (Municipality of Niederanven), Grand Duchy of Luxembourg, or by e-mail toinvestor-relations@orioncarbons.com. Your request must be received by the Company no later than June 18, 2026, 11:59 p.m. CET.

Quorum/Majority

The General Meeting will deliberate validly regardless of the number of Common Shares present or represented by proxy. Resolutions will be adopted by a simple majority of the votes validly cast at the General Meeting, regardless of the number of Common Shares present or represented by proxy, except for the resolution as to the frequency of future Say-on-Pay votes. With respect to the resolution regarding the frequency of future Say-on-Pay votes, the frequency of every one, two or three years which collects the highest number of votes validly cast will be determined to be the preferred frequency recommended by the shareholders of the Company.

Documents

Copies of the full and unabridged text of the documents to be submitted at the General Meeting together with draft resolutions proposed pursuant to the agenda of the General Meeting will be made available on the Company’s website or may be individually requested by you in writing by post to Orion S.A. 6, Route de Trèves, L-2633 Senningerberg (Municipality of Niederanven), Grand Duchy of Luxembourg, or by e-mail toinvestor-relations@orioncarbons.com.

BY ORDER OF THE BOARD OF DIRECTORS

DR. CHRISTIAN EGGERT

Secretary of the Company

Senningerberg, April 24, 2026

CAUTIONARY STATEMENT FOR THE PURPOSES OF THE “SAFE HARBOR” PROVISIONS OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995

This proxy statement (the “Proxy Statement”) contains and refers to certain forward-looking statements with respect to our financial condition, results of operations and business. These statements constitute forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Forward-looking statements are statements of future expectations that are based on management’s current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. You should not place undue reliance on forward-looking statements. Forward-looking statements include, among others, statements concerning our potential exposure to market risks, macroeconomic conditions including tariffs, expected plant uptime, market conditions, anticipated customer demand, expected impacts of operational improvements and foreign exchange, expectations regarding capital expenditures, working capital and free cash flow and other statements expressing management’s expectations, beliefs, estimates, forecasts, projections and assumptions and statements that are not limited to statements of historical or present facts or conditions.

Forward-looking statements are typically identified by words such as “anticipate,” “assume,” “assure,” “believe,” “confident,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “objectives,” “outlook,” “guidance,” “probably,” “project,” “will,” “seek,” “target,” “to be” and other words of similar meaning. These forward-looking statements include, without limitation, statements about the following matters: