Southwestern Ontario is a secondary region of
Southern Ontario in the
Canadian province of
Ontario, centered on the city of
London. It occupies most of a peninsula that is bound on three sides by water:
Lake Huron, including
Georgian Bay, to the north and northwest; the
St. Clair River,
Lake St. Clair, and
Detroit River, to the west; and
Lake Erie to the south. To the east, on land, Southwestern Ontario is bounded by
Central Ontario and the
Golden Horseshoe. The region had a population of 2,504,878 in 2011.