Mainz 05 U19: every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2025-07-01 | Kacper Potulski | Mainz 05 U19 | FSV Mainz 05 II | — |
| 2024-07-01 | Maxim Dal | Mainz 05 U19 | FSV Mainz 05 II | — |
| 2024-07-01 | Kacper Potulski | Mainz 05 U17 | Mainz 05 U19 | — |
| 2024-07-01 | Daniel Gleiber | Mainz 05 U19 | FSV Mainz 05 II | — |
| 2024-07-01 | Aiman Dardari | Mainz 05 U19 | Without Club | — |
| 2023-07-01 | İzzet Erdal | Mainz 05 U19 | Hoffenheim U19 | — |
| 2023-07-01 | Tim Müller | Mainz 05 U19 | FSV Mainz 05 II | — |
| 2023-07-01 | Sinisa Tanjga | Mainz 05 U19 | Vojvodina | Free |
| 2023-07-01 | Maxim Dal | Mainz 05 U17 | Mainz 05 U19 | — |
| 2023-07-01 | Dennis Kaygin | Mainz 05 U19 | Rapid Vienna | Free |
| 2022-11-18 | Brajan Gruda | Mainz 05 U19 | Mainz | — |
| 2022-07-04 | Sinisa Tanjga | Vojvodina U19 | Mainz 05 U19 | Free |
| 2022-07-01 | İzzet Erdal | Mainz 05 U17 | Mainz 05 U19 | — |
| 2022-07-01 | Nelson Weiper | Mainz 05 U19 | Mainz | — |
| 2022-07-01 | Lasse Wilhelm | Mainz 05 U19 | FSV Mainz 05 II | — |
| 2022-07-01 | Daniel Gleiber | Mainz 05 U17 | Mainz 05 U19 | — |
| 2022-07-01 | Aiman Dardari | Mainz 05 U17 | Mainz 05 U19 | — |
| 2022-02-10 | Eniss Shabani | Mainz 05 U19 | FSV Mainz 05 II | — |
| 2022-01-01 | Nelson Weiper | Mainz 05 U17 | Mainz 05 U19 | — |
| 2021-07-01 | Tim Müller | Magdeburg U17 | Mainz 05 U19 | Free |