FC Siena SSD (Serie D: Girone E): every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2026-07-19 | Gabriele Di Paola | FC Siena SSD | Grosseto | Free |
| 2026-07-01 | Player | Prato | FC Siena SSD | Free |
| 2026-01-08 | Player | FC Siena SSD | Grosseto | Free |
| 2025-12-18 | Tommaso Andolfi | Pontedera | FC Siena SSD | Free |
| 2025-11-04 | Gabriele Di Paola | FC Siena SSD | Sansepolcro | Free |
| 2025-08-30 | Player | Ternana U19 | FC Siena SSD | Loan |
| 2025-08-29 | Mirco Lipari | Lumezzane | FC Siena SSD | Free |
| 2025-08-26 | Player | FC Siena SSD | Boreale | Free |
| 2025-07-23 | Niccolo Nardi | ACF Fiorentina | FC Siena SSD | Free |
| 2025-07-22 | Player | FC Siena SSD | Scandicci | Free |
| 2025-07-15 | Player | Ghivizzano Borgo Mozzano | FC Siena SSD | Free |
| 2025-07-13 | Giovanni Farneti | FC Siena SSD | Latina Calcio | Free |
| 2025-07-11 | Player | Gavorrano | FC Siena SSD | Free |
| 2025-07-09 | Player | Piacenza | FC Siena SSD | Free |
| 2025-07-01 | Player | FC Siena SSD | TBC | Free |
| 2025-07-01 | Player | FC Siena SSD | TBC | Free |
| 2025-07-01 | Player | FC Siena SSD | Montevarchi | Free |
| 2025-07-01 | Mauro Semprini | FC Siena SSD | TBC | Free |
| 2025-07-01 | Player | FC Siena SSD | Gavorrano | Free |
| 2025-01-04 | Elvaris Suplja | FC Empoli | FC Siena SSD | Loan |