Avantor, Inc.

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:

AVANTOR, INC.

(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):

2026 Proxy Statement

and Notice of Annual Meeting of Stockholders

Our MissionWe set science in motion to create a better world.

Our VisionFrom discovery to delivery, we are a trusted global provider of mission-critical products and services to customers and suppliers in the life sciences, education, government, advanced technologies and applied materials industries.

Our ValuesOur core set of principles that guide and focus our strategy are our iCARE values:

ACCOUNTABILITY

We hold ourselves accountable for delivering on our promises to our customers, suppliers, shareholders and colleagues to achieve our shared goals. This includes our commitment to meeting the evolving needs of our customers, suppliers, associates, communities and the environment.

RESPECT

We work to build an inclusive culture by seeking to understand each other’s experiences and celebrating our diverse backgrounds. We treat others with dignity and operate with the highest level of integrity. Whether working with internal or external partners, we act as one team and always assume others have good intent.

EXCELLENCE

We never settle for the status quo. We strive to achieve the highest levels of safety, quality, and service. Our passion for continuous improvement is embodied by every employee, the results we achieve together, and the support we provide to our customers. We do our best when we welcome diverse perspectives and work collaboratively to find solutions.

INNOVATION

We know that the best ideas come from the collaboration of diverse perspectives. We empower all employees to explore and contribute ideas that elevate our product and service solutions. We welcome feedback that challenges our thinking and helps us grow. By collaborating with our industry partners, we improve scientific outcomes.

CUSTOMER CENTRIC

Everything we do begins with actively listening and collaborating with our internal and external customers. By understanding their challenges and aspirations, we proactively identify solutions that address their current and future needs.

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Notice of 2026 Annual Meeting of Stockholders

VIRTUAL STOCKHOLDERS MEETING

The Annual Meeting of Stockholders (“Annual Meeting”) of Avantor, Inc. (“Avantor” or the

“Company”) will be held on Thursday, May 7, 2026, at 11:00 a.m. Eastern Time. This year’s

Annual Meeting will be completely virtual, conducted via live audio webcast on the Internet.

Stockholders will be able to listen to and participate in the meeting online, vote their shares

electronically, and submit questions during the meeting by visiting

www.virtualshareholdermeeting.com/AVTR2026. You will need the 16-digit control

number included on your Notice of Internet Availability or proxy card to gain access to the

meeting. Stockholders of record of Avantor common stock at the close of business on

March 13, 2026 will be able to vote online during the meeting. You have received these

proxy materials because our Board of Directors is soliciting your proxy to vote your shares

at the 2026 Annual Meeting.

For more information on how to attend the meeting and vote, see “Questions and Answers

About the Meeting and Voting” in the Proxy Statement.

On behalf of Avantor’s Board of Directors,

CLAUDIUS O. SOKENU

Executive Vice President, Chief Legal and Compliance Officer and Corporate Secretary

This Notice of 2026 Annual Meeting and Proxy Statement, together with our Annual Report

on Form 10-K for the fiscal year ended December 31, 2025, were first made available to

stockholders on or about March 27, 2026.

Important Notice Regarding the Availability of Proxy Materials for the Stockholder

Meeting to Be Held on May 7, 2026: This Notice and Proxy Statement and our Annual

Report are available free of charge at www.proxyvote.com, a site that does not have

“cookies” that identify visitors to the site.

Please refer to the enclosed proxy materials or the information forwarded by your bank,

broker, trustee or other intermediary to see which voting methods are available to you.

Date and TimeThursday, May 7, 202611:00 a.m. Eastern Time

LocationOnline Virtual Meeting at www.virtualshareholdermeeting.com/AVTR2026

Who Can VoteStockholders of record of Avantor common stock at the close of business on March 13, 2026

HOW TO CAST YOUR VOTE Your vote is important! Please cast your vote and play a part in the future of Avantor. You may vote using any one of the following methods. You will need your 16-digit control number from your Notice of Internet Availability or proxy card.

Internetbefore the Annual Meeting atwww.proxyvote.com

Phonecall 1-800-690-6903 toll-free from the U.S. or Canada

Mailreturn the signed proxy card

Virtual meetingonly if you are an eligible stockholder or beneficial owner and have registered and obtained a legal proxy

Your vote is important. We

encourage you to vote by proxy in

advance of the Annual Meeting.

Voting in advance will not affect

your right to attend the Annual

Meeting. Even if you plan to

attend via live audio webcast,

we hope you will vote as soon

as possible.

FORWARD-LOOKING AND CAUTIONARY STATEMENTS

Certain of the statements contained in this Proxy Statement are forward-

looking statements within the meaning of Section 27A of the Securities

Act of 1933, as amended (the "Securities Act") and Section 21E of the

Securities Exchange Act of 1934, as amended (the “Exchange Act”) and

are subject to the safe harbor created thereby under the Private

Securities Litigation Reform Act of 1995. Forward-looking statements

discuss our current expectations and projections relating to our financial

condition, results of operations, plans, objectives, future performance and

business. These statements may be preceded by, followed by or include

the words “aim,” “anticipate,” “assumption,” “believe,” “continue,”

“estimate,” “expect,” “forecast,” “goal,” “guidance,” “intend,” “likely,” “long-

term,” “near-term,” “objective,” “opportunity,” “outlook,” “plan,” “potential,”

“project,” “projection,” “prospects,” “seek,” “target,” “trend,” “can,” “could,”

“may,” “should,” “would,” “will,” the negatives thereof and other words and

terms of similar meaning.

We have based these forward-looking statements on our current

expectations and projections about future events. Although we believe

that our assumptions made in connection with the forward-looking

statements are reasonable, we cannot assure you that the assumptions

and expectations will prove to be correct. Factors that could contribute to

these risks, uncertainties and assumptions include, but are not limited to,

the factors described in “Risk Factors” in our most recent Annual Report

on Form 10-K, as such risk factors may be updated from time to time in

our periodic filings with the SEC. All forward-looking statements speak

only as of the date of this Proxy Statement. We undertake no obligations

to update or revise publicly any forward-looking statements, whether as a

result of new information, future events or otherwise other than as

required under the federal securities laws.

Web links throughout this document are provided for convenience only,

and the content on the referenced website does not constitute a part of

this Proxy Statement.

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