Sunderland U21: every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2025-08-10 | Cuba Mitchell | Sunderland U21 | Bashund. Kings | Free |
| 2025-07-01 | Harrison Jones | Sunderland U21 | Sunderland | — |
| 2024-07-01 | Tom Watson | Sunderland U21 | Sunderland | — |
| 2024-07-01 | Cuba Mitchell | Sunderland U18 | Sunderland U21 | — |
| 2023-07-01 | Tom Watson | Sunderland U18 | Sunderland U21 | — |
| 2023-07-01 | Harrison Jones | Sunderland U18 | Sunderland U21 | — |
| 2023-07-01 | Chris Rigg | Sunderland U21 | Sunderland | — |
| 2022-08-01 | Chris Rigg | Sunderland U18 | Sunderland U21 | — |
| 2020-07-29 | Andrias Edmundsson | Sunderland U23 | Águilas FC | Free |
| 2019-07-01 | Andrias Edmundsson | Sunderland U18 | Sunderland U23 | — |
| 2018-07-01 | Michael Woud | Sunderland U23 | Willem II | — |
| 2018-07-01 | Maksymilian Stryjek | Sunderland U23 | Sunderland | — |
| 2017-08-31 | Maksymilian Stryjek | Sunderland U23 | Accrington | Loan |
| 2017-08-10 | Oscar Krusnell | Sunderland U23 | Hammarby | — |
| 2017-07-11 | Dan Casey | Sunderland U23 | Bohemians | Free |
| 2017-07-01 | Oscar Krusnell | Sunderland U18 | Sunderland U23 | — |
| 2017-07-01 | Michael Woud | Sunderland U18 | Sunderland U23 | — |
| 2016-07-01 | Dan Casey | Sunderland U18 | Sunderland U23 | — |
| 2015-07-01 | Maksymilian Stryjek | Sunderland U18 | Sunderland U21 | — |
| 2013-07-01 | Jordan Pickford | Sunderland U21 | Sunderland | — |