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) 2025 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 18, 2025 (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. 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 meeting and appointing a proxy under “Questions and Answers About the Proxy Materials, Annual Meeting and Voting” beginning on page 57 of the proxy statement.

Sincerely yours,

Hassane El-Khoury

President and Chief Executive Officer

April 3, 2025

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FORTHE STOCKHOLDER MEETING TO BE HELD ON MAY 15, 2025.Our proxy statement for the 2025 Annual Meeting of Stockholders and our annual reportto stockholders for the fiscal year ended December 31, 2024 are available atwww.onsemi.com/annualdocs.

ON SEMICONDUCTOR CORPORATION

Proxy Statement

TABLE OF CONTENTS

onsemi 2025 Proxy Statement i

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement includes “forward-looking statements,” as that term is defined in Section 27A of the Securities Act 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 expectations, forecasts, estimates and assumptions as of the date of this proxy statement, and involve risks, uncertainties and other factors that could cause results or events to differ materially from those expressed in the forward-looking statements.

Important factors that can 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, 2024, filed with the SEC on February 10, 2025 (Form 10-K). Many of the assumptions upon which such forward-looking statements are based are likely to change after the date on which 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.

GLOSSARY OF COMMON TERMS

ii onsemi 2025 Proxy Statement