Lake Simcoe is a lake in Southern Ontario, Canada, the fourth-largest lake wholly in the province, after Lake Nipigon, Lac Seul, and Lake Nipissing. At the time of the first European contact in the 17th century the lake was called Ouentironk ("Beautiful Water") by the Wyandot (Huron) people. It was also known as Lake Toronto until it was renamed by John Graves Simcoe, the first Lieutenant-Governor of Upper Canada, in memory of his father, Captain John Simcoe, Royal Navy.