The 1980–81 OHL season was the first season of the Ontario Hockey League, having been renamed from the Ontario Major Junior Hockey League. Twelve teams each played 68 games. The Kitchener Rangers won the J. Ross Robertson Cup, defeating the Sault Ste. Marie Greyhounds.
Oshawa Generals defeat Peterborough Petes 3–2
Niagara Falls Flyers defeat Toronto Marlboros 3–2
Kingston Canadians defeat Ottawa 67's 4–2, 1 tie
Sault Ste. Marie Greyhounds defeat Oshawa Generals 4–2
Windsor Spitfires defeat Brantford Alexanders 4–2
Kitchener Rangers defeat Niagara Falls Flyers 4–2, 1 tie
Sault Ste. Marie Greyhounds defeat Kingston Canadians 4–2, 1 tie
Kitchener Rangers defeat Windsor Spitfires 4–0, 1 tie
Kitchener Rangers defeat Sault Ste. Marie Greyhounds 4–1, 1 tie