Colchester United's U23s will play 25 games in their league season in 2020/21 with players also representing the first team.
The fixtures for the current season are as follows:-
| Date | Opponents | Venue | Kick-off/Score |
| SEPTEMBER 2020 | |||
| Monday 14th September | Watford (A) | St Albans | 0-1 |
|
Monday 21st September |
Charlton Athletic (H) | JobServe Community Stadium | 0-0 |
| OCTOBER 2020 | |||
| Sunday 4th October | Swansea City (A) | Swansea Academy | 3-3 |
| Monday 12th October | Ipswich Town (H) | JobServe Community Stadium | 0-2 |
| Tuesday 20th October | Barnsley (A) | Oakwell Training Ground | 2-2 |
| Tuesday 27th October | Sheffield United (H) | Florence Park | 1-4 |
| NOVEMBER 2020 | |||
| Monday 2nd November | Nottingham Forest (A) | The Nigel Doughty Acadmey | 3-0 |
| Wednesday 11th November | Birmingham City (H) | Maldon and Tiptree | 1-2 |
| Tuesday 24th November | QPR (H) | Florence Park | 0-0 |
| Saturday 28th November | Cardiff City (H) | Florence Park | 2-0 |
| DECEMBER 2020 | |||
| Tuesday 15th December | Millwall (A) | Millwall Training Ground | 6-1 |
| JANUARY 2021 | |||
| Tuesday 12th January | Bristol City (A) | WSM FC Optima Stadium | 3-1 |
| Monday 18th January | Watford (H) | Florence Park | 2-2 |
| Tuesday 26th January | Ipswich | Playford Road | 1pm |
| FEBRUARY 2021 | |||
| Monday 1st February | Swansea City (H) | Florence Park | 1pm |
| Tuesday 9th February | Cardiff City (A) | Leckwith Stadium | 1pm |
| Tuesday 16th February | QPR (A) | Harligton | 1pm |
| Monday 22nd February | Chalrton Athletic (A) | Dartford FC | 1pm |
| MARCH 2021 | |||
| Tuesday 2nd March | Bristol City (H) | Florence Park | 12pm |
| Tuesday 9th March | Millwall (H) | Florence Park | 1pm |
| Monday 22nd March | Crewe Alexandra (A) | Alexandra Park | 1pm |
| APRIL 2021 | |||
| Tuesday 6th April | Wigan Athletic (H) | Florence Park | 1pm |
| Tuesday 20th April | Sheffield Wednesday (A) | Stockbridge Park Steels FC | 1pm |
| Monday 26th April | Hull City (H) | Florence Park | 1pm |
| MAY 2021 | |||
| Monday 3rd May | Coventry City (A) | Alan Higgs Centre | 1pm |