The 1921 season was the 38th season of regional competitive soccer in Australia.
| Federation | Competition [1] | Grand Final | Regular Season | ||||
|---|---|---|---|---|---|---|---|
| Champions | Score | Runners-up | Winners | Runners-up | Third place | ||
| Northern District British Football Association | Northern NSW Football League [2] | West Wallsend Bluebells | 2–0 | Cessnock | West Wallsend Bluebells | Wallsend Royals | Weston |
| Australian Soccer Association | Sydney Metropolitan First Division [3] | Pyrmont | Unknown | Pyrmont | Granville | Unknown | |
| Queensland British Football Association | Brisbane Area League [4] | Not played | Dinmore Bush Rats | Bundamba Rangers | Thistle | ||
| South Australian British Football Association | South Australia Division One [5] | Not played | Cheltenham | North Adelaide | Sturt | ||
| Tasmanian Soccer Association | Tasmanian Division One [6] | South Hobart | Unknown | Tamar | Unknown | ||
| Anglo-Australian Football Association | Victorian League Division One [7] | Not played | Windsor | Northumberland & Durham | Footscray Thistle | ||
| Western Australian Soccer Football Association | Western Australia Division One [8] | Not played | Thistle | Claremont | Perth City United | ||
| Federation | Competition [9] | Winners | Runners-up | Venue | Result |
|---|---|---|---|---|---|
| Northern District British Football Association | Ellis Cup [10] | West Wallsend Bluebells | Cessnock | – | 2–0 |
| New South Wales British Football Association | Gardiner Challenge Cup [11] | West Wallsend (3/3) | Granvile (2/3) | – | 3–1 |
| South Australian British Football Association | South Australia Federation Cup [12] | South Adelaide | Cheltenham | – | 3–2 |
| Tasmanian Soccer Association | Falkinder Cup [13] | South Hobart | Hobart | – | 2–0 |
| Anglo-Australian Football Association | Dockerty Cup [14] | Northumberland & Durham United (2/0) | Submarine Depot (0/1) | – | 2–0 (R) |
(Note: figures in parentheses display the club's competition record as winners/runners-up.)