Company: BCDRF
Filing Date: 2025-09-11
Form Type: 6-K
Source: 0000950103-25-011516
Chunk: 1

Company: Banco Santander, S.A.
Filing Date: 2025-09-11
Form: 6-K
Chunk 1
---
EU          |           35,318 |                     8.2309 |
| 10/09/2025 | SAN      | Purchase    | XMAD          |          676,960 |                     8.4220 |
| 10/09/2025 | SAN      | Purchase    | CEUX          |           73,946 |                     8.4266 |
| 10/09/2025 | SAN      | Purchase    | TQEX          |           17,245 |                     8.4208 |
| 10/09/2025 | SAN      | Purchase    | AQEU          |           31,849 |                     8.4418 |
|            |          |             | TOTAL         |        4,600,000 |                            |

Issuer name: Banco Santander, S.A. - LEI
5493006QMFDDMYWIAM13

Reference of the financial instrument: ordinary
shares - Code ISIN ES0113900J37

Detailed information of the transactions carried
out within the referred period is attached as Annex I.

Boadilla del Monte (Madrid), 11 September 2025

<div align='center'>ANNEX I</div>

Detailed information
on each of the transactions carried out within the context of the Buy-back Programme between 04/09/2025 and 10/09/2025 (both inclusive)

(https://www.santander.com/content/dam/santander-com/es/documentos/cumplimiento/do-anexo-i-04-a-10-sept-2025.pdf)

<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: | September 11, 2025 |     | Banco Santander, S.A. 
 By:                   | /s/ Pedro de Mingo Kaminouchi |                              |
|:------|:-------------------|:----|:----------------------|:------------------------------|:-----------------------------|
|       |                    |     |                       | Name:                         | Pedro de Mingo Kaminouchi    |
|       |                    |     |                       | Title:                        | Head of Corporate Compliance |