ENTEGRIS 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

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Entegris, Inc.

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Guiding what we do and how we do it.MissionTo help our customers improve their productivity, performance, and technology by providing enhancing materials and process solutions for the most advanced manufacturing environments.

Letter to Stockholders

Dear Entegris Stockholders:I am honored to lead this exceptional company and grateful for the trust the Board and our stockholders have bestowed on me. During my first six months as CEO and nearly two years on the Entegris Board, I have developed a deep appreciation for the Company’s culture, its commitment to innovation and to its customers. I am excited by the significant opportunities ahead.While 2025 presented a year of slower growth for Entegris amid industry headwinds, it was a pivotal year of strategic positioning. We secured key wins at our customers’ most advanced technology nodes, laying the foundation for the growth opportunities we see ahead. Our unit driven revenue increased approximately 2% compared to 2024, in-line with industry wafer starts, driven by strong increases in the critical product areas of CMP consumables, liquid filtration and selective etch. Cash flow was a highlight of our business in 2025. For the full year, we delivered a significant increase in our free cash flow margin, which increased to 12.7% of sales. This enabled incremental repayment of approximately $300 million of debt in 2025, reducing our leverage and strengthening our financial position. We expect to build on this momentum in 2026. We believe the industry backdrop entering 2026 is more constructive. The continued advancement of our customers’ technology roadmaps creates significant opportunities for Entegris. As device architecture becomes more sophisticated and complexity intensifies, our expertise in materials science and purity becomes even more critical for our customers’ performance and yield. Additionally, ongoing node transitions provide more opportunities for Entegris to increase content per wafer and support our ability to sustain market outperformance over the long-term.Entegris is well positioned to capitalize on the next phase of semiconductor growth. We are focused on securing strong positions of record (PORs) at the new technology nodes of advanced logic, 3D NAND and DRAM. Having reached the conclusion of our multiyear manufacturing CAPEX investment cycle that began in 2022, we will utilize the resulting additional manufacturing capacity to support future growth and expect to deliver more than $1 billion in incremental revenue with limited further investment. In addition, we are making progress with the ramp up of our Kaohsiung, Taiwan facility, further strengthening our local-for-local strategy in Asia. Together, these actions are expected to improve our competitiveness, profitability, free cash flow and strengthen our balance sheet, while also positioning Entegris to compound stockholder value over time.My leadership team and I are excited for 2026 and committed to continuing to build on our strong foundation as we advance our strategy and, in doing so, deliver long-term value to customers and stockholders.I appreciate your continued trust, support and investment in Entegris.David ReederPresident, Chief Executive Officer and DirectorMarch 23, 2026

Notice of 2026 Annual Meeting of Stockholders

Stockholders will also transact such other business as may properly come before the meeting and at any adjournment or postponement thereof.

The 2026 Annual Meeting of Stockholders of Entegris, Inc. will be held on Wednesday, May 6, 2026, at 3:00 p.m., local time, online in a virtual meeting format, via the internet, with no physical in-person meeting of the stockholders. Stockholders attending our virtual Annual Meeting will be able to vote and submit questions during the Annual Meeting. Further information about how to attend the Annual Meeting online, vote your shares online during the Annual Meeting and submit questions is included in the accompanying proxy statement.

We will begin mailing a Notice of Internet Availability of Proxy Materials (the “Notice”) on or about March 23, 2026 to stockholders of record at the close of business on March 20, 2026. The Notice contains instructions on how to access our proxy statement, our fiscal year 2025 Annual Report to Stockholders and the form of proxy on the Internet, as well as instructions on how to request a paper copy of the proxy materials.

Stockholders of record at the close of business on March 20, 2026 are entitled to vote at the Annual Meeting and any adjournments or postponements thereof.

By order of the Board of Directors,

Joe Colella

Senior Vice President, General Counsel, Chief Compliance Officer and Secretary

Notice of 2026 Annual Meeting of Stockholders

How to Vote

Important Notice Regarding the Availability of Proxy Materials for the 2026 Annual Meeting of Stockholders to be Held on May 6, 2026 – the Proxy Statement, Form of Proxy and the Annual Report to Stockholders are available at http://investor.entegris.com/financials/.

This Proxy Statement is furnished in connection with the solicitation of proxies by the Board of Directors (the “Board”) of Entegris, Inc., a Delaware corporation (“Entegris,” the “Company,” “us,” “we” or “our”), for use at the 2026 Annual Meeting of Stockholders to be held on Wednesday, May 6, 2026 at 3:00 p.m., local time, and at any adjournments or postponements of that meeting (the “Annual Meeting” or the “Annual Meeting of Stockholders”). This Proxy Statement, the foregoing Notice of Annual Meeting of Stockholders, the enclosed Form of Proxy and the Company’s 2025 Annual Report to Stockholders are first being mailed or given to stockholders on or about March 23, 2026. The content of any website referred to in this Proxy Statement is not a part of and is not incorporated by reference in this Proxy Statement.

Table of Contents

Forward-Looking Statements

This Proxy Statement contains “forward-looking statements”. The words “believe,” “expect,” “anticipate,” “intend,” “estimate,” “forecast,” “project,” “should,” “may,” “will,” “would” or the negative thereof and similar expressions are intended to identify such forward-looking statements. These forward-looking statements may include statements about market and technology trends, including the duration and drivers of any growth trends, the Company’s future performance and growth, the Company’s corporate social responsibility program and other matters. These forward-looking statements are based on current management expectations and assumptions only as of the date of this Proxy Statement, are not guarantees of future performance and involve substantial risks and uncertainties that are difficult to predict and could cause actual results to differ materially from the results expressed in, or implied by, these forward-looking statements. These risks and uncertainties include, but are not limited to, the risk factors and additional information described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025 under the caption “Risk Factors”. Except as required under the federal securities laws and rules and regulations of the Securities and Exchange Commission, the Company undertakes no obligation to update publicly any forward-looking statements or information contained herein, which speak as of their respective dates.