| P | # | Player | Born | Height | Weight | Contract | |
|---|---|---|---|---|---|---|---|
| M | Martin Ødegaard | 1998-12-17 | 176 | 68 |
| Date | Player | From | To | Status | Src |
|---|---|---|---|---|---|
| 30.Jun | Marcos Llorente (M) | Deportivo Alavés | Real Madrid Castilla | Confirmed | |
| 10.Aug | Marcos Llorente (M) | Real Madrid Castilla | Deportivo Alavés | Confirmed | |
| 30.Jun | Mario Hermoso (D) | Real Valladolid | Real Madrid Castilla | Confirmed | |
| 30.Jun | Raúl De Tomas (F) | Córdoba CF | Real Madrid Castilla | Confirmed | |
| 3.Sep | Eero Markkanen (F) | Real Madrid Castilla | RoPS | Confirmed | |
| 21.Aug | Eero Markkanen (F) | Real Madrid Castilla | Free Agent | Rumour | |
| 31.Jul | José Rodríguez (M) | Real Madrid Castilla | Galatasaray SK | Confirmed | |
| 20.Aug | Lucas Vázquez (F) | Real Madrid Castilla | RCD Espanyol | Confirmed | |
| 13.Aug | Borja García (M) | Real Madrid Castilla | Córdoba CF | Confirmed | |
| 6.Aug | Omar Mascarell (M) | Real Madrid Castilla | Derby County | Confirmed |