Simcoe South was a federal electoral district represented in the Canadian House of Commons from 1867 to 1925, and from 1979 to 1988. It was located north of Toronto in the province of Ontario. It was initially created by the British North America Act of 1867 when the County of Simcoe was divided into two ridings, to be called the South and North Ridings in the Legislative Assembly of the Province of Canada. The South Riding consisted of the Townships of West Gwillimbury, Tecumseh, Innisfil, Essa, Tossorontio, Mulmur, and the Village of Bradford.