SUZ 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of August, 2026.

Commission File Number 001-38755

Suzano S.A. (Exact name of registrant as specified in its charter)

SUZANO INC. (Translation of Registrant’s Name into English)

Av. Professor Magalhaes Neto, 1,752 10th Floor, Rooms 1010 and 1011 Salvador, Brazil 41 810-012 (Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F. Form 20-F ☑    Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

Enclosures:

Exhibit 99.1 – Executive Vice Presidency Organizational Changes

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, thereunto duly authorized.

Date: August 04ᵗʰ, 2026

Document

SUZANO S.A.

Publicly Held Company

Corporate Taxpayer ID (CNPJ/ME)

No. 16.404.287/0001-55

Company Registry (NIRE) 29.3.0001633-1

NOTICE TO THE MARKET

São Paulo, August 4th, 2026 – Suzano S.A. ("Company" or "Suzano") (B3: SUZB3 / NYSE: SUZ), in line with best corporate governance practices, hereby informs its shareholders and the market in general that it has received the resignation of its Executive Vice President of Pulp Industrial Operations, Engineering and Energy, Mr. Aires Galhardo, effective August 28, 2026

Following Mr. Galhardo's departure, the Company's Board of Directors has approved the appointment of the current Executive Vice President, Mr. Carlos Aníbal Fernandes de Almeida Júnior, as Executive Vice President of Pulp Industrial Operations, Engineering and Energy. He will also continue to oversee Procurement, Certification Strategy, and the leadership of Futuragene.

Mr. Carlos Aníbal Fernandes de Almeida Júnior has been with Suzano for more than 23 years and brings extensive knowledge of both the Company and the pulp and paper industry. Throughout his career at Suzano, he has led several key business areas, including the Pulp Business Unit, the Paper Business Unit, and the Forestry Division..

The members of the Board of Directors express their sincere appreciation and deep gratitude to Mr. Aires Galhardo for his more than 21 years of dedicated service and significant contributions to the Company across several strategic areas of the business.

São Paulo, August 4th, 2026.

Marcos Moreno Chagas Assumpção

Executive Vice President of Finance and Investor Relations