Fourcorner Lake (French: lac Fourcorner) is a lake in the municipality of Dysart et al, Haliburton County in Central Ontario, Canada. It is partly within Algonquin Provincial Park and is in the Ottawa River drainage basin. The lake takes its name from its location at a quadripoint, the junction point of four geographic townships: Harburn at northwest, Bruton at the northeast, Harcourt at the southeast, and Dudley at the southwest.