Lake Nipigon is part of the Great Lakes drainage basin. It is the largest lake entirely within the boundaries of the Canadian province of Ontario.

Nipigon is a township in Thunder Bay District, Northwestern Ontario, Canada, located along the west side of the Nipigon River and south of the small Helen Lake running between Lake Nipigon and Lake Superior. Lake Nipigon is located approximately 25 kilometres (16 mi) north of Nipigon. Located at latitude 49.0125° N, Nipigon is the northernmost community on the Great Lakes.