Head to Head
| England U23 Development League | 2021/02/16 13:00 | Cardiff U23 v Millwall U23 | W | 3-0 |
| England U23 Development League | 2020/11/25 11:00 | Millwall U23 v Cardiff U23 | L | 2-0 |
| England U23 Development League | 2020/02/03 14:00 | Millwall U23 v Cardiff U23 | L | 3-0 |
| England U23 Development League | 2019/10/07 12:00 | Cardiff U23 v Millwall U23 | W | 2-1 |
| England U23 Development League | 2019/02/18 13:31 | Millwall U23 v Cardiff U23 | W | 0-1 |
| England U23 Development League | 2018/09/24 11:57 | Cardiff U23 v Millwall U23 | D | 2-2 |
| England U23 Development League | 2018/01/08 11:58 | Cardiff U23 v Millwall U23 | D | 1-1 |
| England U23 Development League | 2017/10/16 13:25 | Millwall U23 v Cardiff U23 | D | 1-1 |
Home History
| England U23 Development League | 2021/09/21 12:00 | Cardiff U23 v Sheff Utd U23 | W | 2-0 |
| England U23 Development League | 2021/09/10 10:00 | Sheff Wed U23 v Cardiff U23 | W | 0-3 |
| England U23 Development League | 2021/08/29 14:00 | Cardiff U23 v Peterborough U23 | W | 3-1 |
| England U23 Development League | 2021/08/16 12:00 | Cardiff U23 v Wigan U23 | W | 1-0 |
| England U23 Development League | 2021/05/03 14:00 | Barnsley U23 v Cardiff U23 | D | 1-1 |
| England U23 Development League | 2021/04/27 12:00 | Cardiff U23 v Coventry U23 | L | 1-6 |
| England U23 Development League | 2021/04/23 18:00 | Nottm Forest U23 v Cardiff U23 | W | 1-2 |
| England U23 Development League | 2021/04/13 12:00 | Cardiff U23 v Sheff Utd U23 | L | 0-2 |
Away History
| England U23 Development League | 2021/09/21 13:00 | Millwall U23 v Barnsley U23 | W | 4-0 |
| England U23 Development League | 2021/09/13 12:00 | Coventry U23 v Millwall U23 | L | 4-1 |
| England U23 Development League | 2021/08/23 18:00 | Hull U23 v Millwall U23 | L | 3-1 |
| England U23 Development League | 2021/08/17 12:00 | Millwall U23 v Crewe U23 | W | 1-0 |
| UK Friendlies | 2021/07/27 18:15 | Eastbourne Borough v Millwall U23 | L | 2-1 |
| UK Friendlies | 2021/07/15 18:30 | Dulwich v Millwall U23 | W | 0-2 |
| England U23 Development League | 2021/05/04 16:30 | Hull U23 v Millwall U23 | W | 0-2 |
| England U23 Development League | 2021/04/27 13:00 | Millwall U23 v Sheff Utd U23 | L | 1-2 |