8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 17, 2026

Avantor, Inc.

(Exact name of registrant as specified in its charter)

Radnor Corporate Center, Building One, Suite 200

100 Matsonford Road

Radnor, Pennsylvania 19087

(Address of principal executive offices, including zip code)

(610) 386-1700

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐    Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). ☐ Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.02.    Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On April 17, 2026, Avantor, Inc. (the “Company”) informed Benoit Gourdier, the Company’s Executive Vice President, Bioscience and Medtech Products, that he would be transitioning to a new role supporting the Company’s segment integration activities, after which it is expected that he would depart the Company no later than December 31, 2026.

Item 7.01. Regulation FD Disclosure.

On April 23, 2026, the Company issued a press release announcing the hiring of Ludovic Brellier to serve as the Company’s Executive Vice President, Bioscience and Medtech Products and Chief Transformation Officer effective May 1, 2026. A copy of the press release is furnished herewith as Exhibit No. 99 to this Current Report on Form 8-K, and shall not be deemed filed for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section and shall not be deemed to be incorporated by reference into any filing by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01.    Financial Statements and Exhibits.

(d) Exhibits.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

avantorannouncesludovicb

News release FOR IMMEDIATE RELEASE Avantor® Announces Ludovic Brellier as Executive Vice President, Bioscience & Medtech Products (BMP) & Chief Transformation Officer RADNOR, Pa. – April 23, 2026 – Avantor, Inc. (NYSE: AVTR), a leading global provider of mission- critical products and services to customers in the life sciences and advanced technology industries, today announced that Ludovic Brellier will join the company as Executive Vice President, Bioscience & Medtech Products (BMP) & Chief Transformation Officer on May 1, 2026. In this role, Mr. Brellier will be responsible for growing the BMP business and improving operational performance. He will also lead the Revival Management Office, driving transformation initiatives across the enterprise. Mr. Brellier is an accomplished executive with deep operational experience across healthcare and strategic business transformation. He joins Avantor from Danaher, where he was most recently President of Cytiva’s Hardware Solutions business, leading five business units responsible for early innovation through manufacturing and commercialization of services for the biopharma industry. While at Cytiva, Mr. Brellier previously served as President of Integrated Solutions & Services and VP Business Operations. He also led the effort to establish Cytiva as a standalone operating company within Danaher as well as the integration of Pall Life Sciences and Cytiva. “Ludovic is a skilled operator who has a successful track record of growing bioprocessing businesses both organically and inorganically, and our BMP segment is a strong platform that has a lot of potential for growth under his leadership,” said Emmanuel Ligner, Avantor’s President and CEO. “As we execute Revival across our enterprise, Ludovic’s past transformation and integration experience will be critical.” Ligner concluded. Mr. Brellier added, “Avantor’s bioprocessing platform has leading product brands with rich legacies and strong customer preference. I look forward to leveraging my manufacturing and commercialization skills to enhance our operations and drive sustainable growth in the business by enabling the product brands to reach their full potential. The successful execution of Revival will be critical to the success of both Avantor’s business segments,” Brellier concluded. Benoit Gourdier, current Executive Vice President of Avantor’s BMP Segment, will stay with the company until on or before the end of 2026 to ensure a smooth transition. About Avantor Avantor® is a leading life science tools company and global provider of mission-critical products and services to the life sciences and advanced technology industries. We work side-by-side with customers at every step of the scientific journey to enable breakthroughs in medicine,

page | 2 healthcare, and technology. Our portfolio is used in virtually every stage of the most important research, development and production activities at more than 300,000 customer locations in 180 countries. For more information, visit avantorsciences.com and find us on LinkedIn, X (Twitter) and Facebook. Investor Relations Contact Chris Fidyk Vice President, Investor Relations Avantor Chris.Fidyk@avantorsciences.com Global Media Contact Eric Van Zanten Head of External Communications Avantor 610-529-6219 Eric.VanZanten@avantorsciences.com SOURCE: Avantor and Financial News