Bilbao U19: every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2023-07-01 | Aingeru Olabarrieta | Bilbao U19 | Bilbao Athletic | — |
| 2022-07-01 | Mikel Jauregizar | Bilbao U19 | CD Basconia | — |
| 2022-07-01 | Aingeru Olabarrieta | Bilbao U18 | Bilbao U19 | — |
| 2021-07-01 | Álex Padilla | Bilbao U19 | CD Basconia | — |
| 2021-07-01 | Unai Gómez | Bilbao U19 | CD Basconia | — |
| 2021-07-01 | Unai Egiluz | Bilbao U19 | CD Basconia | — |
| 2021-07-01 | Mikel Jauregizar | Bermeo FT | Bilbao U19 | — |
| 2021-07-01 | Alejandro Rego | Bilbao U19 | CD Basconia | — |
| 2020-08-01 | Mikel Goti | Bilbao U19 | CD Basconia | — |
| 2020-07-01 | Álex Padilla | Bilbao U18 | Bilbao U19 | — |
| 2020-07-01 | Unai Gómez | Bilbao U18 | Bilbao U19 | — |
| 2020-07-01 | Unai Egiluz | Bilbao U18 | Bilbao U19 | — |
| 2020-07-01 | Nico Williams | Bilbao U19 | Bilbao Athletic | — |
| 2020-07-01 | Nico Serrano | Bilbao U19 | Bilbao Athletic | — |
| 2020-07-01 | Hugo Rincón | Bilbao U18 | Bilbao U19 | — |
| 2020-07-01 | Hugo Rincón | Bilbao U19 | CD Basconia | — |
| 2020-07-01 | Alejandro Rego | Bilbao U18 | Bilbao U19 | — |
| 2019-07-01 | Nico Williams | Bilbao U18 | Bilbao U19 | — |
| 2019-07-01 | Nico Serrano | Bilbao U18 | Bilbao U19 | — |
| 2019-07-01 | Mikel Goti | Bilbao U18 | Bilbao U19 | — |