The Toronto St. Michael's Majors were a major junior ice hockey team in the Ontario Hockey League, based in Toronto, Ontario, Canada. The most recent franchise was revived on August 15, 1996. In 2007, the team relocated to Mississauga, Ontario and became the Mississauga St. Michael's Majors until 2012. The hockey program was founded and operated by St. Michael's College School in 1906, and adopted the name "Majors" in 1934, and was commonly referred to as St. Mike's Majors.

The Ontario Hockey League is one of the three major junior ice hockey leagues which constitute the Canadian Hockey League. The league is for players aged 16–20. There are currently 20 teams in the OHL: seventeen in Ontario, two in Michigan, and one in Pennsylvania.