| Competition: | South Western League |
| Season: | 1990–91 |
| Prevseason: | 1989–90 |
| Nextseason: | 1991–92 |
The 1990–91 South Western Football League season was the 40th in the history of South Western League. The league consisted of 17 teams.[1]
| Team | Location | County | Stadium | |
|---|---|---|---|---|
| Bodmin | Cornwall | Priory Park | ||
| St Blazey | St Blazey | Cornwall | Blaise Park | |
| Falmouth | Cornwall | Bickland Park | ||
| Newquay | Cornwall | Mount Wise | ||
| St Austell | Cornwall | Poltair Park | ||
| Torpoint Athletic | Torpoint | Cornwall | The Mill | |
| Truro | Cornwall | Treyew Road | ||
| Bugle | Bugle | Cornwall | ||
| Appledore/B A A C | Appledore | Devon | Marshford | |
| Wadebridge | Cornwall | Bodieve Park | ||
| Millbrook | Millbrook | Cornwall | Jenkins Park | |
| Tavistock | Tavistock | Devon | Langsford Park | |
| Porthleven | Porthleven | Cornwall | Gala Parc | |
| Clyst Rovers | Clyst Honiton | Devon | Waterslade Park | |
| Launceston | Launceston | Cornwall | Pennygillam | |
| Holsworthy | Holsworthy | Devon | Upcott Field | |
| Penzance | Penzance | Cornwall | Penlee Park |
| Competition: | South Western League |
| Season: | 1990–91 |
| Promoted: | None |
| Relegated: | None |
The division featured 17 teams, all from last season.