| 2021-12-11 | GrimsbyvChesterfieldNational League · England | 0–1 | National League · England |
| 2021-12-04 | Dag and RedvGrimsbyNational League · England | 3–2 | National League · England |
| 2021-11-23 | SolihullvGrimsbyNational League · England | 2–0 | National League · England |
| 2021-11-19 | GrimsbyvSouthendNational League · England | 1–0 | National League · England |
| 2021-11-13 | AldershotvGrimsbyNational League · England | 2–1 | National League · England |
| 2021-10-30 | GrimsbyvNotts CountyNational League · England | 0–1 | National League · England |
| 2021-10-26 | WealdstonevGrimsbyNational League · England | 1–0 | National League · England |
| 2021-10-23 | GrimsbyvYeovilNational League · England | 2–0 | National League · England |
| 2021-10-09 | WokingvGrimsbyNational League · England | 0–1 | National League · England |
| 2021-10-05 | AltrinchamvGrimsbyNational League · England | 2–3 | National League · England |
| 2021-10-02 | GrimsbyvDover AthleticNational League · England | 6–0 | National League · England |
| 2021-09-28 | BromleyvGrimsbyNational League · England | 3–1 | National League · England |
| 2021-09-25 | MaidenheadvGrimsbyNational League · England | 1–1 | National League · England |
| 2021-09-18 | GrimsbyvEastleighNational League · England | 2–0 | National League · England |
| 2021-09-14 | GrimsbyvWrexhamNational League · England | 3–1 | National League · England |
| 2021-09-11 | TorquayvGrimsbyNational League · England | 1–3 | National League · England |
| 2021-09-04 | GrimsbyvBarnetNational League · England | 4–3 | National League · England |
| 2021-08-31 | StockportvGrimsbyNational League · England | 0–0 | National League · England |
| 2021-08-28 | GrimsbyvWeymouthNational League · England | 1–0 | National League · England |
| 2021-05-08 | CambridgevGrimsbyLeague Two · England | 3–0 | League Two · England |
| 2021-05-01 | GrimsbyvPort ValeLeague Two · England | 1–0 | League Two · England |
| 2021-04-27 | ExetervGrimsbyLeague Two · England | 3–2 | League Two · England |
| 2021-04-24 | OldhamvGrimsbyLeague Two · England | 1–2 | League Two · England |
| 2021-04-20 | GrimsbyvMorecambeLeague Two · England | 0–3 | League Two · England |
| 2021-04-17 | GrimsbyvBoltonLeague Two · England | 2–1 | League Two · England |
| 2021-04-10 | BradfordvGrimsbyLeague Two · England | 1–0 | League Two · England |
| 2021-04-05 | GrimsbyvCheltenhamLeague Two · England | 1–1 | League Two · England |
| 2021-04-02 | SalfordvGrimsbyLeague Two · England | 1–1 | League Two · England |
| 2021-03-27 | GrimsbyvWalsallLeague Two · England | 1–1 | League Two · England |
| 2021-03-23 | BarrowvGrimsbyLeague Two · England | 0–1 | League Two · England |
| 2021-03-20 | MansfieldvGrimsbyLeague Two · England | 2–2 | League Two · England |
| 2021-03-17 | GrimsbyvTranmereLeague Two · England | 0–0 | League Two · England |
| 2021-03-13 | GrimsbyvColchesterLeague Two · England | 0–0 | League Two · England |
| 2021-03-09 | CarlislevGrimsbyLeague Two · England | 1–1 | League Two · England |
| 2021-03-06 | GrimsbyvForest GreenLeague Two · England | 1–2 | League Two · England |
| 2021-03-02 | GrimsbyvLeyton OrientLeague Two · England | 0–1 | League Two · England |
| 2021-02-27 | HarrogatevGrimsbyLeague Two · England | 1–0 | League Two · England |
| 2021-02-23 | GrimsbyvCrawley TownLeague Two · England | 2–1 | League Two · England |
| 2021-02-06 | Newport CountyvGrimsbyLeague Two · England | 1–0 | League Two · England |
| 2021-01-30 | GrimsbyvStevenageLeague Two · England | 1–2 | League Two · England |
| 2021-01-23 | ScunthorpevGrimsbyLeague Two · England | 3–0 | League Two · England |
| 2021-01-16 | GrimsbyvSouthendLeague Two · England | 0–0 | League Two · England |
| 2021-01-09 | Port ValevGrimsbyLeague Two · England | 3–0 | League Two · England |
| 2021-01-02 | GrimsbyvCambridgeLeague Two · England | 1–2 | League Two · England |