Company: BCDRF
Filing Date: 2025-07-23
Form Type: 6-K
Source: 0000950103-25-009151
Chunk: 0

Company: Banco Santander, S.A.
Filing Date: 2025-07-23
Form: 6-K
Chunk 0
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<div align='center'>FORM 6-K

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Report of Foreign Issuer

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

the Securities Exchange Act of 1934

For the month of July, 2025

Commission File Number: 001-12518

Banco Santander, S.A.

(Exact name of registrant as specified in its charter)

Ciudad Grupo Santander

28660 Boadilla del Monte (Madrid) Spain

(Address of principal executive office)</div>

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 |

<div align='center'>Banco Santander, S.A.

TABLE OF CONTENTS</div>

Item 1

Banco Santander, S.A. (“Santander”
or the “Bank”), in compliance with the Securities Market legislation, hereby communicates the following:

Santander hereby announces that it
shall disclose its first half financial results for 2025 next Wednesday, 30 July 2025.

To this end, a presentation will
be given to analysts via audio conference at 10:00 a.m. (Madrid time), which can be followed through the Bank’s corporate website
www.santander.com. The associated documentation will be made public prior to its commencement
through a communication to the CNMV and publication on the aforementioned corporate website.

At 12:00 p.m. (Madrid time), a presentation
to share such results with media will take place at the Ciudad Grupo Santander in Boadilla del Monte (Madrid), to which media may attend
either in-person or by videoconference.

Boadilla del Monte (Madrid), 23 July
2025

<div align='center'>SIGNATURE</div>

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: | July 23, 2025 |     | Banco Santander, S.A. 
 By:                   | /s/ Pedro de Mingo Kaminouchi |                              |
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