York—Simcoe is a federal electoral district in Ontario, Canada, that has been represented in the House of Commons of Canada from 1968 to 1979, from 1988 to 1997 and since 2004. It covers part of the region north of Toronto by Lake Simcoe. It has existed on three separate occasions. Its first incarnation was created in 1966 from parts of Dufferin—Simcoe and York North. It existed until 1976 when it was split between York North, Simcoe South, and York—Peel. Its current incarnation came into being in 2003 made up of parts of Simcoe—Grey, York North, and Barrie—Simcoe—Bradford.