Cardiff City Yo: every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2023-07-01 | Ronan Kpakio | Cardiff City Yo | Cardiff U18 | — |
| 2022-08-01 | Charlie Crew | Cardiff City Yo | Leeds U18 | — |
| 2022-07-01 | Dylan Lawlor | Cardiff City Yo | Cardiff U18 | — |
| 2021-07-01 | Joel Colwill | Cardiff City Yo | Cardiff U18 | — |
| 2019-07-01 | Eli King | Cardiff City Yo | Cardiff U18 | — |
| 2018-07-01 | Rubin Colwill | Cardiff City Yo | Cardiff U18 | — |
| 2018-07-01 | Isaak Davies | Cardiff City Yo | Cardiff U18 | — |
| 2016-07-01 | Rabbi Matondo | Cardiff City Yo | Man City U18 | — |
| 2016-07-01 | Chris Popov | Cardiff City Yo | Man Utd Youth | Free |
| 2015-07-01 | Mark Harris | Cardiff City Yo | Cardiff U18 | — |
| 2011-07-01 | Tom Lockyer | Cardiff City Yo | Brist. Rov. U18 | Free |