The 1989–90 season was the 19th in the history of Essex Senior Football League a football competition in England.[1]
The league featured 16 clubs which competed in the league last season, no new clubs joined the league this season.
Brightlingsea United were champions, winning their second Essex Senior League title in a row and transferred to the Eastern Counties League.
| Competition: | Essex Senior Football League |
| Season: | 1989–90 |
| Winners: | Brightlingsea United |
| Matches: | 240 |
| Total Goals: | 818 |
| Prevseason: | 1988–89 |
| Nextseason: | 1990–91 |