| 3. Round | 01/11/2020 | Real Sociedad B | - | CD Laredo | 3:0 | ||||
| 4. Round | 08/11/2020 | Barakaldo CF | - | Real Sociedad B | 1:4 | ||||
| 5. Round | 14/11/2020 | SD Amorebieta | - | Real Sociedad B | 2:1 | ||||
| 6. Round | 22/11/2020 | Real Sociedad B | - | Real Unión | 0:1 |  |
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| 7. Round | 29/11/2020 | Arenas de Getxo | - | Real Sociedad B | 1:1 | |
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| 9. Round | 12/12/2020 | Club Portugalete | - | Real Sociedad B | 1:1 | ||||
| 10. Round | 19/12/2020 | Real Sociedad B | - | Athletic Club B | 1:2 | ||||
| 8. Round | 03/01/2021 | Real Sociedad B | - | Racing Santander | 4:1 | |
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| 11. Round | 09/01/2021 | CD Alavés B | - | Real Sociedad B | 0:1 | |
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| 12. Round | 16/01/2021 | SD Leioa | - | Real Sociedad B | 1:1 | ||||
| 14. Round | 31/01/2021 | CD Laredo | - | Real Sociedad B | 0:0 | ||||
| 15. Round | 07/02/2021 | Real Sociedad B | - | Barakaldo CF | 2:0 |  |
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| 16. Round | 13/02/2021 | Real Sociedad B | - | SD Amorebieta | 2:1 | ||||
| 17. Round | 20/02/2021 | Real Unión | - | Real Sociedad B | 3:1 | |
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| 19. Round | 07/03/2021 | Racing Santander | - | Real Sociedad B | 0:1 | |
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| 21. Round | 21/03/2021 | Athletic Club B | - | Real Sociedad B | 1:2 | |
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| 22. Round | 28/03/2021 | Real Sociedad B | - | CD Alavés B | 4:1 |
Spain