ON SEMICONDUCTOR CORP

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

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

ON Semiconductor Corp oration

(Name of Registrant as Specified In Its Charter)

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

Payment of Filing Fee (Check all boxes that apply):

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

Stockholders will also consider such other business as may properly come before the ON Semiconductor Corporation (the Company) 2026 Annual Meeting of Stockholders (including any adjournment or postponement thereof, the annual meeting). Only stockholders of record as of the close of business on March 17, 2026 (the record date) are entitled to notice of, and to vote at, the annual meeting.

Your vote is very important to us. As in prior years, most stockholders will receive a notice with information on how to access our proxy materials and vote online. You may vote online or by phone as described in your proxy card or voting instruction form. If you receive a paper copy of our proxy materials, you may also vote by returning the proxy card or voting instruction form included in those materials. Shares cannot be voted by marking, writing on and returning the notice. Even if you plan to attend the annual meeting in person, we encourage you to vote your shares in advance by any of the below methods to ensure that your vote will be represented.

We recommend that you review further information on the process for, and deadlines applicable to, voting, attending the annual meeting and appointing a proxy under “Questions and Answers About the Proxy Materials, Annual Meeting and Voting” beginning on page 59 of the proxy statement.

By Order of the Board of Directors,

Hassane El-Khoury

President and Chief Executive Officer

April 2, 2026

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FORTHE STOCKHOLDER MEETING TO BE HELD ON MAY 14, 2026.Our proxy statement for the 2026 Annual Meeting of Stockholders and our annual reportto stockholders for the fiscal year ended December 31, 2025 are available atwww.onsemi.com/annualdocs.

ON SEMICONDUCTOR CORPORATION

Proxy Statement

TABLE OF CONTENTS

onsemi 2026 Proxy Statement i

CAUTIONARY STATEMENT

This proxy statement includes “forward-looking statements,” as that term is defined in Section 27A of the Securities Act of 1933, as amended and Section 21E of the Exchange Act. All statements, other than statements of historical facts, included or referenced in this proxy statement could be deemed forward-looking statements, particularly statements about our plans, strategies and prospects. Forward-looking statements are often characterized by the use of words such as “believes,” “estimates,” “expects,” “projects,” “may,” “will,” “intends,” “plans,” “anticipates,” “should,” “commitments” or similar expressions, or by discussions of strategy, plans or intentions. All forward-looking statements in this proxy statement are made based on our current expectations, forecasts, estimates and assumptions and involve risks, uncertainties and other factors that could cause results or events to differ materially from those expressed in the forward-looking statements.

Factors that could cause our actual results to differ materially from those anticipated in forward-looking statements include, but are not limited to, those described in more detail under the heading “Risk Factors” in our annual report on Form 10-K for the year ended December 31, 2025, filed with the SEC on February 9, 2026 (Form 10-K). Many of the assumptions the forward-looking statements are based upon are likely to change after the date the forward-looking statements are made. Further, we may make changes to our business plans that could affect our results. Readers are cautioned not to place undue reliance on forward-looking statements. We assume no obligation to update such information, which speaks only as of the date made, except as may be required by law. This proxy statement also contains non-GAAP financial measures. Please refer to the Appendix to this proxy statement for our calculation and reconciliation of certain non-GAAP financial measures and for information regarding certain limitations and considerations regarding the use of non-GAAP financial measures. Website links and other reports referenced in this proxy statement are for convenience only. Information contained in or accessible through such website links and other reports is not incorporated herein and does not constitute a part of this proxy statement.

GLOSSARY OF COMMON TERMS

ii onsemi 2026 Proxy Statement