6-K

UNITED STATESSECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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 February, 2026

Commission File Number: 001-34476

BANCO SANTANDER (BRASIL) S.A.

(Exact name of registrant as specified in its charter)

Avenida Presidente Juscelino Kubitschek, 2041 and 2235Bloco A – Vila OlimpiaSão Paulo, SP 04543-011Federative Republic of 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: Form 20-F ___X___ 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):

Yes _______ No ___X____

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):

Yes _______ No ___X____

Indicate by check mark whether by furnishing the information contained in this Form, the Registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934:

Yes _______ No ___X____

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b):  N/A

BANCO SANTANDER (BRASIL) S.A.

Public Company with Authorized Capital

Corporate Taxpayer ID (CNPJ/MF) No. 90.400.888/0001-42

Company Registration (NIRE) No. 35.300.332.067

Minutesof the Board of Directors Meeting held on February 27^th^, 2026

DATE, TIME AND PLACE: On February 27^th^, 2026, at 10 a.m. by conference call, the Board of Directors of Banco Santander (Brasil) S.A. (“Company” or “Santander”) have met, with the attendance of all its members.

CALL NOTICE AND NOTICE: The call was waived in view of the attendance of all members of the Board of Directors.

MEETING BOARD: Deborah Stern Vieitas, Chairman. Bruno Garcia Rosa Carneiro, Secretary.

AGENDA: Approve the Management Report and the Company's Financial Statements in accordance with IFRS and the Prudential Conglomerate’s Financial Statements for the fourth quarter and fiscal year of 2025, accompanied by the notes and unqualified report issued by PricewaterhouseCoopers Auditores Independentes, according to the Management Proposal and to the favorably recommendation of the Audit Committee.

RESOLUTIONS: After review and discussion of the agenda, the members of the Board of Directors unanimously and without restriction voted to approve the Management Report and the Company's Financial Statements in accordance with IFRS and the Prudential Conglomerate’s Financial Statements for the fourth quarter and the fiscal year ended on December 31, 2025, accompanied by the notes and unqualified report issued by PricewaterhouseCoopers Auditores Independentes, according to the Management Proposal and to the favorably recommendation of the Audit Committee.

ADJOURNMENT: There being no further matters to be resolved, the Meeting was finalized, and these minutes have been prepared and send to be electronically signed by the attendees. Board: Deborah Stern Vieitas, President. Bruno Garcia Rosa Carneiro, Secretary. Signatures: Mrs. Deborah Stern Vieitas – President; Mr. Javier Maldonado Trinchant – Vice President; and Messrs. Antonio Carlos Quintella, Cristina San Jose Brosa, Cristiana Almeida Pipponzi, Deborah Patricia Wright, Ede Ilson Viani, José de Paiva Ferreira, Mario Roberto Opice Leão, Nitin Prabhu, Pedro Augusto de Melo and Vanessa de Souza Lobato Barbosa – Directors. São Paulo, February 27^th^, 2026.

I certify that this is a true transcript of the minutes recorded in the Minutes of the Board of Directors Meetings Book of the Company.

Bruno Garcia Rosa Carneiro

Secretary

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, thereto duly authorized.

Date: February 27, 2026