| 1 | Sat 10 Oct 2020 | 20-0 v Bolton WanderersBolton Wanderers 0-0 Grimsby Town | Sky Bet League Two |
| 2 | Tue 13 Oct 2020 | 2 3-1 v Cheltenham TownCheltenham Town 1-3 Grimsby Town | Sky Bet League Two |
| 3 | Sat 17 Oct 2020 | 23-2 v Leyton OrientLeyton Orient 2-3 Grimsby Town | Sky Bet League Two |
| 4 | Tue 20 Oct 2020 | 2 1-2 v Harrogate TownGrimsby Town 1-2 Harrogate Town | Sky Bet League Two |
| 5 | Sat 24 Oct 2020 | 21-1 v Carlisle UnitedGrimsby Town 1-1 Carlisle United | Sky Bet League Two |
| 6 | Tue 27 Oct 2020 | 20-1 v Forest Green RoversForest Green Rovers 1-0 Grimsby Town | Sky Bet League Two |
| 7 | Sat 31 Oct 2020 | 20-0 v StevenageStevenage 0-0 Grimsby Town | Sky Bet League Two |
| 8 | Tue 3 Nov 2020 | 21-0 v BarrowGrimsby Town 1-0 Barrow | Sky Bet League Two |
| 9 | Sat 21 Nov 2020 | 2 0-5 v Tranmere RoversTranmere Rovers 5-0 Grimsby Town | Sky Bet League Two |
| 10 | Tue 24 Nov 2020 | 22-1 v Crawley TownCrawley Town 1-2 Grimsby Town | Sky Bet League Two |
| 11 | Tue 1 Dec 2020 | 2 1-4 v Exeter CityGrimsby Town 1-4 Exeter City | Sky Bet League Two |
| 12 | Sat 5 Dec 2020 | 21-2 v Colchester UnitedColchester United 2-1 Grimsby Town | Sky Bet League Two |
| 13 | Tue 8 Dec 2020 | 2 0-2 v Newport CountyGrimsby Town 0-2 Newport County | Sky Bet League Two |
| 14 | Tue 15 Dec 2020 | 21-3 v Southend UnitedSouthend United 3-1 Grimsby Town | Sky Bet League Two |
| 15 | Sat 19 Dec 2020 | 21-0 v Scunthorpe UnitedGrimsby Town 1-0 Scunthorpe United | Sky Bet League Two |
| 16 | Tue 22 Dec 2020 | 21-2 v Bradford CityGrimsby Town 1-2 Bradford City | Sky Bet League Two |
| 17 | Sat 26 Dec 2020 | 21-3 v MorecambeMorecambe 3-1 Grimsby Town | Sky Bet League Two |
| 18 | Tue 29 Dec 2020 | 20-0 v Oldham AthleticGrimsby Town 0-0 Oldham Athletic | Sky Bet League Two |
| 19 | Sat 2 Jan 2021 | 21-2 v Cambridge UnitedGrimsby Town 1-2 Cambridge United | Sky Bet League Two |
| 20 | Sat 9 Jan 2021 | 20-3 v Port ValePort Vale 3-0 Grimsby Town | Sky Bet League Two |
| 21 | Sat 16 Jan 2021 | 20-0 v Southend UnitedGrimsby Town 0-0 Southend United | Sky Bet League Two |
| 22 | Sat 23 Jan 2021 | 20-3 v Scunthorpe UnitedScunthorpe United 3-0 Grimsby Town | Sky Bet League Two |
| 23 | Sat 30 Jan 2021 | 21-2 v StevenageGrimsby Town 1-2 Stevenage | Sky Bet League Two |
| 24 | Tue 23 Feb 2021 | 22-1 v Crawley TownGrimsby Town 2-1 Crawley Town | Sky Bet League Two |
| 25 | Sat 27 Feb 2021 | 20-1 v Harrogate TownHarrogate Town 1-0 Grimsby Town | Sky Bet League Two |
| 26 | Sat 6 Mar 2021 | 21-2 v Forest Green RoversGrimsby Town 1-2 Forest Green Rovers | Sky Bet League Two |
| 27 | Tue 9 Mar 2021 | 21-1 v Carlisle UnitedCarlisle United 1-1 Grimsby Town | Sky Bet League Two |
| 28 | Sat 13 Mar 2021 | 20-0 v Colchester UnitedGrimsby Town 0-0 Colchester United | Sky Bet League Two |
| 29 | Wed 17 Mar 2021 | 20-0 v Tranmere RoversGrimsby Town 0-0 Tranmere Rovers | Sky Bet League Two |
| 30 | Sat 20 Mar 2021 | 22-2 v Mansfield TownMansfield Town 2-2 Grimsby Town | Sky Bet League Two |
| 31 | Tue 23 Mar 2021 | 21-0 v BarrowBarrow 0-1 Grimsby Town | Sky Bet League Two |
| 32 | Sat 27 Mar 2021 | 21-1 v WalsallGrimsby Town 1-1 Walsall | Sky Bet League Two |
| 33 | Fri 2 Apr 2021 | 21-1 v Salford CitySalford City 1-1 Grimsby Town | Sky Bet League Two |
| 34 | Mon 5 Apr 2021 | 21-1 v Cheltenham TownGrimsby Town 1-1 Cheltenham Town | Sky Bet League Two |
| 35 | Sat 10 Apr 2021 | 20-1 v Bradford CityBradford City 1-0 Grimsby Town | Sky Bet League Two |
| 36 | Sat 17 Apr 2021 | 22-1 v Bolton WanderersGrimsby Town 2-1 Bolton Wanderers | Sky Bet League Two |
| 37 | Sat 1 May 2021 | 21-0 v Port ValeGrimsby Town 1-0 Port Vale | Sky Bet League Two |
| 38 | Sat 8 May 2021 | 20-3 v Cambridge UnitedCambridge United 3-0 Grimsby Town | Sky Bet League Two |