Southwestern Ontario was first settled by Europeans in the early 18th century, when it was part of the Royal Province of New France. One of the oldest continuous settlements in the region is Windsor, which originated as a southerly extension of the settlement of Fort Detroit in 1701. With the transfer of New France to British control in 1763, the region was part of the British Province of Quebec, 1774 to 1791; the Province of Upper Canada, 1791 to 1841; and the Canada West division of the Province of United Canada, 1841 to Confederation in 1867, when United Canada was formally partitioned into the provinces of Ontario and Quebec.

During the 19th century and early 20th century, the largest city in Southwestern Ontario was Windsor; however, as both cities grew, Windsor was outpaced by the faster growth of London, and passed the mantle of regional anchor to that city in the 1960s.

Southwestern Ontario is a prosperous agricultural region whose chief crops are tobacco, sweet corn, soybean, winter wheat, canola, and tomatoes.[citation needed] Dairy and beef farming, breeding and training of standardbred horses and wine growing and production are also important industries. Its climate is among the mildest in Canada. Although brief periods of winter can be severe, summers are hot and humid with a longer growing season than in most of the country.

A large section of Southwestern Ontario was part of the Talbot Settlement, and the region has benefited from the settlement’s facilitation of agriculture and of trade in general. Its economy is heavily tied in with that of the midwestern United States, in particular the border state of Michigan. Auto manufacturing and parts, agriculture and hi-tech industries are key components of the region’s economy. The region also provides important transportation routes for commercial trucking, railway and tanker shipping from Detroit-Windsor and Port Huron, Michigan-Sarnia linking Canada with major markets in the eastern and midwestern United States.