1990–91 WOAA Senior League season

The 1990–91 WOAA Senior League season was the 1st season of the WOAA Senior AA Hockey League. The league played a 24-game regular season which began in October 1990 and concluded in February 1991. The post-season began in February 1991 and concluded in April 1991.

The Arthur Tigers won the WOAA Grand Championship, defeating the Durham Thundercats in the final round of the playoffs.

Final standings
Note: GP = Games played; W = Wins; L= Losses; OTL = Overtime losses; GF = Goals for; GA = Goals against; Pts = Points; Green shade = Clinched playoff spot

Scoring leaders
Note: GP = Games played; G = Goals; A = Assists; Pts = Points; PIM = Penalty minutes

(2) Palmerston 81's vs. (7) Milverton Four Wheel Drives
Note: Game three played in Harriston, Ontario