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

OTHER RELEVANT INFORMATION

Reference is made to our notice of inside information of 21 November 2022 (official registry number 1669), relating to the buyback programme of own shares (the "Buy-back Programme") approved by the Board of Directors of Banco Santander.

Pursuant to article 5 of Regulation (EU) no. 596/2014 on Market Abuse of 16 April 2014, and articles 2.2 and 2.3 of Commission Delegated Regulation (EU) 2016/1052, of 8 March 2016, the Bank informs, on the basis of the information received from Goldman Sachs International as intermediary in charge of executing the Buy-back Programme, that it has carried out the following transactions over its own shares between 21 and 28 December (both inclusive):

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), 29 December 2022

ANNEX I

Detailed information on each of the transactions carried out within the context of the Buy-back Programme between 21/12/2022 and 28/12/2022 (both inclusive)