| Middlesbrough FC U23 | Season 2023/2024 | 35 Players/Coaches |
| Middlesbrough FC U23 | Season 2022/2023 | 43 Players/Coaches |
| Middlesbrough FC U23 | Season 2021/2022 | 47 Players/Coaches |
| Middlesbrough FC U23 | Season 2020/2021 | 45 Players/Coaches |
| Middlesbrough FC U23 | Season 2019/2020 | 38 Players/Coaches |
| Middlesbrough FC U23 | Season 2018/2019 | 36 Players/Coaches |
| Middlesbrough FC U23 | Season 2017/2018 | 38 Players/Coaches |
| Middlesbrough FC U23 | Season 2016/2017 | 29 Players/Coaches |
| Middlesbrough FC U21 | Season 2015/2016 | 34 Players/Coaches |
| Middlesbrough FC U21 | Season 2014/2015 | 25 Players/Coaches |
| Middlesbrough FC U21 | Season 2013/2014 | 23 Players/Coaches |
| Middlesbrough FC U21 | Season 2012/2013 | 19 Players/Coaches |
| Middlesbrough FC U21 | Season 2011/2012 | 1 Players/Coaches |
England 
![Middlesbrough FC [U18]](https://s.hs-data.com/bilder/wappen/mini/28109.gif?fallback=png "Middlesbrough FC [U18]"){kind=small}
![Middlesbrough FC [U16]](https://s.hs-data.com/bilder/wappen/mini/41296.gif?fallback=png "Middlesbrough FC [U16]"){kind=small}
![Middlesbrough FC [Youth]](https://s.hs-data.com/bilder/wappen/mini/22403.gif?fallback=png "Middlesbrough FC [Youth]"){kind=small}
![Middlesbrough FC [Youth B]](https://s.hs-data.com/bilder/wappen/mini/25283.gif?fallback=png "Middlesbrough FC [Youth B]"){kind=small}