The 1930–31 season was the 22nd in the history of the Isthmian League, an English football competition.
Wimbledon were champions, winning their first Isthmian League title.
| Competition: | Isthmian League |
| Season: | 1930–31 |
| Winners: | Wimbledon |
| Matches: | 182 |
| Total Goals: | 788 |
| Prevseason: | 1929–30 |
| Nextseason: | 1931–32 |