The 2009–10 season was the 68th in the history of Eastern Counties Football League a football competition in England.[1]
Needham Market were champions, winning their first Eastern Counties Football League title and were promoted to the Isthmian League for the first time in their history.
| Competition: | Eastern Counties Football League Premier Division |
| Season: | 2009–10 |
| Winners: | Needham Market |
| Promoted: | Needham Market |
| Matches: | 380 |
| Total Goals: | 1230 |
| Prevseason: | 2008–09 |
| Nextseason: | 2010–11 |
The Premier Division featured 19 clubs which competed in the division last season, along with three new clubs, promoted from Division One:
| Competition: | Eastern Counties Football League Division One |
| Season: | 2009–10 |
| Winners: | Great Yarmouth Town |
| Promoted: | Brantham Athletic Clacton Great Yarmouth Town |
| Matches: | 342 |
| Total Goals: | 1196 |
| Prevseason: | 2008–09 |
| Nextseason: | 2010–11 |
Division One featured 17 clubs which competed in the division last season, along with two new clubs: