Castellón: every transfer in and out, fees paid and earned, squad market value, €5.7m spent and €12m earned.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-08-06 | Awer Mabil | Castellón | Melbourne City FC | Free |
| 2026-07-23 | Salva Ruiz | Castellón | SD Huesca | Free |
| 2026-07-21 | Antonio Gala | Campobasso | Castellón | Free |
| 2026-07-18 | Rodrigo Rêgo | Brighton & Hove Albion | Castellón | Loan |
| 2026-07-14 | Amir Saipi | FC Lugano | Castellón | €1m |
| 2026-07-10 | Serpeta | Castellón | Águilas CF | Loan |
| 2026-07-08 | Jari Vlak | ADO Den Haag | Castellón | €600k |
| 2026-07-08 | Hamza Bellari | Valencia II | Castellón | Free |
| 2026-07-07 | Sergi Torner | Castellon II | Castellón | Free |
| 2026-07-07 | Ismael Fadel | Castellón | UD Ibiza | Loan |
| 2026-07-04 | Iñigo Córdoba | Burgos CF | Castellón | Free |
| 2026-07-02 | Álex Calatrava | Castellón | RCD Espanyol Barcelona | €5m |
| 2026-07-01 | Carlos Segura | Castellon II | Castellón | Free |
| 2026-07-01 | Álvaro Martín | FC Andorra | Castellón | Free |
| 2026-07-01 | Juanjo Nieto | NK Celje | Castellón | Free |
| 2026-07-01 | Jozhua Vertrouwd | Castellón | Rayo Vallecano | €1.5m |
| 2026-07-01 | Brian Cipenga | Castellón | UD Almería | Free |
| 2026-01-29 | Serpeta | Castellón | Unionistas de Salamanca | Loan |
| 2026-01-26 | Nick Markanich | Castellón | Houston | Loan |
| 2026-01-23 | Álvaro García | Merida | Castellón | Free |