Trout Lake is a lake in municipalities of East Ferris and North Bay, Nipissing District in Northeastern Ontario, Canada, approximately east of the much larger Lake Nipissing. Trout Lake is the source of the Mattawa River and a significant body of water on a well-known historic North American voyageur (fur-trading) route. It is about long and wide and exits eastward into the Mattawa River, which flows via the Ottawa River to the St. Lawrence River. Some of the most difficult portages are found on this part of the voyageur route between Trout Lake and the end of the Mattawa River, e.g., Portage de Mauvaise Musique, located at the Talon Chute (named after explorer and voyageur Jean Talon).