Willem II U21 (U21 Divisie 1): every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2025-07-20 | Myles Veldman | Willem II U21 | Nevėžis | Free |
| 2025-07-01 | Player | AZ U19 | Willem II U21 | Free |
| 2025-07-01 | Karst de Leeuw | Willem II U21 | Willem II | Free |
| 2025-07-01 | Remi Akanni | Willem II U21 | Quick Boys | Free |
| 2025-05-06 | Uriël van Aalst | Willem II U21 | Willem II | Free |
| 2024-09-02 | Player | NEC Nijmegen | Willem II U21 | Free |
| 2024-08-06 | Player | Willem II U21 | Smitshoek | Free |
| 2024-07-01 | Myles Veldman | Cambuur U21 | Willem II U21 | Free |
| 2024-07-01 | Player | Willem II U21 | Blauw Geel '38 | Free |
| 2024-07-01 | Player | Willem II U21 | Kozakken Boys | Free |
| 2024-07-01 | Naïm Matoug | Willem II U21 | VVV-Venlo | Free |
| 2024-07-01 | Per van Loon | Willem II U21 | Willem II | Free |
| 2024-01-01 | Jayden Houtriet | Willem II U21 | Willem II | Free |
| 2023-10-24 | Player | Willem II U21 | Willem II | Free |
| 2023-10-24 | Khaled Razak | Willem II U21 | Willem II | Free |
| 2023-01-01 | Niels van Berkel | Willem II U21 | Willem II | Free |
| 2023-01-01 | Amine Lachkar | Willem II U21 | Willem II | Free |
| 2022-08-10 | Player | Willem II U21 | FC Dordrecht | Free |
| 2022-07-28 | Player | Willem II U21 | SV 1919 Straelen | Free |
| 2022-07-23 | Player | Willem II U21 | Willem II | Free |