| 1991 SANFL season | |
|---|---|
| Teams | 9 |
| Premiers | North Adelaide 13th premiership |
| Minor premiers | South Adelaide 4th minor premiership |
| Magarey Medallist | Mark Naley South Adelaide (29 votes) |
| Ken Farmer Medallist | Scott Morphett Woodville-West Torrens (99 Goals) |
| Attendance | |
| Matches played | 105 |
| Total attendance | 560,114 (5,334 per match) |
| Highest | 39,276 (Grand Final, North Adelaide vs. West Adelaide) |
The 1991 SANFL season was the 112th season of the highest level Australian rules football Competition in South Australia.Woodville and West Torrens merged at the end of the 1990 season resulting in the competition reducing from 10 to 9 clubs.