| Address: | Avd. Matapiñonera s/n., 28700 San Sebastián de los Reyes (Madrid) |
| Telephone: | 91 651 86 54 |
| Fax: | 91 663 86 48 |
| Founded: | 1971 |
| President: | José María CASTRO Gómez |
| Official website: | www.ud-sanse.com |
| E-mail: | info@ud-sanse.com |
| Manager: |
| Name: | Nuevo Matapiñonera |
| Capacity: | 3,000 |
| Segunda Federación Grupo 5 2025/26 |
|
| 16-Nov-2025 | 2a Fed (11) | Socuéllamos | 0-2 | San Sebastián |
| 22-Nov-2025 | 2a Fed (12) | San Sebastián | 2-1 | Orihuela |
| 29-Nov-2025 | 2a Fed (13) | Elche Ilicitano | 1-2 | San Sebastián |
| 07-Dec-2025 | 2a Fed (14) | San Sebastián | 0-0 | Intercity |
| 14-Dec-2025 | 2a Fed (15) | Quintanar del Rey | 0-2 | San Sebastián |
| 20-Dec-2025 | 2a Fed (16) | San Sebastián | 1-2 | Tenerife B |
| 04-Jan-2026 | 2a Fed (17) | Real Madrid C | 1-2 | San Sebastián |
| 11-Jan-2026 | 2a Fed (18) | San Sebastián | 1-1 | Rayo Majadahonda |
| 18-Jan-2026 | 2a Fed (19) | Alcalá | - | San Sebastián |
| 24-Jan-2026 | 2a Fed (20) | San Sebastián | - | Socuéllamos |
| 01-Feb-2026 | 2a Fed (21) | Navalcarnero | - | San Sebastián |
| 08-Feb-2026 | 2a Fed (22) | San Sebastián | - | Elche Ilicitano |
| 15-Feb-2026 | 2a Fed (23) | Rayo Vallecano B | - | San Sebastián |
| 22-Feb-2026 | 2a Fed (24) | San Sebastián | - | Quintanar del Rey |
| 01-Mar-2026 | 2a Fed (25) | Coria | - | San Sebastián |
| 08-Mar-2026 | 2a Fed (26) | San Sebastián | - | Fuenlabrada |