Real Unión Club (Primera Federación): every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-07-27 | Ekain Azkune | Racing Ferrol | Real Unión Club | Free |
| 2026-07-25 | Martín Merquelanz | Kitchee | Real Unión Club | Free |
| 2026-07-16 | Santi Miguélez | Real Unión Club | Guadalajara | Free |
| 2026-07-07 | Ignacio Tellechea | Real Unión Club | Cacereño | Free |
| 2026-07-02 | Jordi González-Pola González | AD Alcorcón | Real Unión Club | Free |
| 2026-07-01 | Player | Merida | Real Unión Club | Free |
| 2026-07-01 | Aitor Galarza | Eibar II | Real Unión Club | Free |
| 2026-07-01 | Ander Martín | FC Cartagena | Real Unión Club | Free |
| 2026-07-01 | Javier Mecerreyes | Real Unión Club | Alcoyano | Free |
| 2025-10-03 | Koldo Obieta Alberdi | Real Unión Club | Kerala Blasters | Free |
| 2025-08-26 | Player | Real Unión Club | Conquense | Free |
| 2025-08-14 | Player | RZ Deportivo Aragón | Real Unión Club | Loan |
| 2025-08-10 | Ander Vidorreta | Real Unión Club | Pontevedra | Free |
| 2025-08-04 | Player | Real Unión Club | Sestao River | Free |
| 2025-07-27 | Player | Real Unión Club | UD Logroñés | Free |
| 2025-07-23 | Santi Miguélez | Real Oviedo II | Real Unión Club | Free |
| 2025-07-21 | David Fernández | Langreo | Real Unión Club | Free |
| 2025-07-19 | Iván Ayllón | Real Unión Club | Talavera CF | Free |
| 2025-07-18 | Player | Aston Villa U21 | Real Unión Club | Free |
| 2025-07-16 | Player | Real Sociedad III | Real Unión Club | Free |