AVTR-A 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 the appropriate box):

Your Vote Counts! Get informed before you vote View the Notice of Proxy Statement, Annual Report,1234567890123456789012345678901234567890, 123456789012345678 9012345678901234567890, 1234567890123456789012345678901234567890, 12345678901234567890123456789012345 67890 online OR you can receive a free paper copy of voting material(s) by requesting prior to <matcutoff>. If you would like to request a copy of the voting material(s), you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # FLASHID-JOB# Ricky Campana P.O. Box 123456 Suite 500 51 Mercedes Way Edgewood, NY 11717 148,294 322,224 1 OF 2 30# XXXX XXXX XXXX XXXX AVANTOR, INC. 2022 Annual Meeting Vote by May 11, 2022 11:59 PM ET AVANTOR, INC. RANDOR CORPORATE CENTER BUILDING ONE, SUITE 200 100 MATSONFORD ROAD RADNOR, PA 19087 You invested in AVANTOR, INC. and it’s time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the stockholder meeting to be held on May 12, 2022. View the Notice & Proxy Statement, Form 10-K, Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 28, 2022. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an Vote Virtually at the Meeting* May 12, 2022 11:00 AM EDT Virtually at: www.virtualshareholdermeeting.com/AVTR2022 *Please check the meeting materials for any special requirements for meeting attendance.

THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming shareholder meeting. Please follow the instructions on the reverse side to vote these important matters. Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Sign up for E-delivery”. Voting Items Board Recommends SHARE CLASSES REPRESENTED FOR VOTING This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. 1. Election of Directors Nominees: 1a. Juan Andres For 1b. John Carethers For 1c. Matthew Holt For 1d. Lan Kang For 1e. Joseph Massaro For 1f. Mala Murthy For 1g. Jonathan Peacock For 1h. Michael Severino For 1i. Christi Shaw For 1j. Michael Stubblefield For 1k. Gregory Summe For 2. Ratification of the Appointment of Deloitte & Touche LLP as the Company’s independent registered accounting firm for 2022. For 3. Approve, on an Advisory Basis, Named Executive Officer Compensation. For NOTE: To consider such other business as may properly come before the meeting or any adjournment or postponement thereof.Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Sign up for E-delivery”.