The 1989–90 United Counties League season was the 83rd in the history of the United Counties League, a football competition in England.
| Competition: | United Counties League Premier Division |
| Season: | 1989–90 |
| Winners: | Bourne Town |
| Matches: | 462 |
| Total Goals: | 1286 |
| Prevseason: | 1988–89 |
| Nextseason: | 1990–91 |
The Premier Division featured 20 clubs which competed in the division last season, along with two new clubs:
Also, Stewart & Lloyds Corby changed name to Hamlet Stewart & Lloyds.
| Competition: | United Counties League Division One |
| Season: | 1989–90 |
| Winners: | Daventry Town |
| Matches: | 342 |
| Total Goals: | 1165 |
| Prevseason: | 1988–89 |
| Nextseason: | 1990–91 |
Division One featured 18 clubs which competed in the division last season, along with one new club: