Southwestern Ontario is a secondary region of Southern Ontario in the Canadian province of Ontario. It occupies most of the Ontario Peninsula bounded by 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 2,583,544 in 2016. It is sometimes further divided into "Midwestern Ontario" covering the eastern half of the area and the heart of Southwestern Ontario encompassing the western half of the region. Source: Wikipedia (en)