United States

Securities and Exchange Commission

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

of the

Securities Exchange Act of 1934

For the month of

November 2025

Vale S.A.

Praia de Botafogo nº 186, 18º andar, Botafogo
22250-145 Rio de Janeiro, RJ, Brazil

(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.)

(Check One) Form 20-F x Form 40-F ¨

 Vale informs about Vale Day 2025 Rio de Janeiro, November 25, 2025 - Vale S.A. ("Vale") informs that its annual meeting with capital market participants will be held in London, United Kingdom, on December 2, 2025. The event will be broadcast live via video webcast in English, with simultaneous translation into Portuguese, starting at 10:00 a.m. Brasília time, 8:00 a.m. New York time, and 1:00 p.m. London time. Further information, including the link to access the webcast, will be available on Vale’s website (www.vale.com), in the Investors section, as of December 1, 2025. Marcelo Feriozzi BacciExecutive Vice President, Finance and Investor Relations For further information, please contact: Vale.RI@vale.com Thiago Lofiego: thiago.lofiego@vale.com Mariana Rocha: mariana.rocha@vale.com Luciana Oliveti: luciana.oliveti@vale.com Pedro Terra: pedro.terra@vale.com Patricia Tinoco: patricia.tinoco@vale.com This press release may include statements that present Vale’s expectations about future events or results. All statements, when based upon expectations about the future, involve various risks and uncertainties. Vale cannot guarantee that such statements will prove correct. These risks and uncertainties include factors related to the following: (a) the countries where we operate, especially Brazil and Canada; (b) the global economy; (c) the capital markets; (d) the mining and metals prices and their dependence on global industrial production, which is cyclical by nature; and (e) global competition in the markets in which Vale operates. To obtain further information on factors that may lead to results different from those forecast by Vale, please consult the reports Vale files with the U.S. Securities and Exchange Commission (SEC), the Brazilian Comissão de Valores Mobiliários (CVM) and in particular the factors discussed under “Forward-Looking Statements” and “Risk Factors” in Vale’s annual report on Form 20-F. Press Release  

Signatures

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.