The 1989–90 season was the 48th in the history of Eastern Counties Football League a football competition in England.
[1] Sudbury Town were champions for the second time in a row, winning their seventh Eastern Counties Football League title and were promoted to the Southern Football League for the first time in their history.
The Premier Division featured 19 clubs which competed in the division last season, along with two new clubs, promoted from Division One: Division One featured twelve clubs which competed in the division last season, along with five new clubs: Also, Loadwell Ipswich changed name to Ipswich Wanderers.