Santander Holdings USA (SOV) 10-Q 2021 Q3 Quarterly report

Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report on Form 10-Q for the year ended September 30, 2021 of Santander Holdings USA, Inc. (the "Company") as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Timothy Wennes, President and Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1)the Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2)the information contained in the Report fairly presents, in all in material respects, the financial condition and results of operations of the Company.

/s/ Timothy Wennes

Name: Timothy Wennes

Title: President and Chief Executive Officer

November 2, 2021