The Seguin River is a river in Parry Sound District in central Ontario, Canada that empties into Parry Sound on Georgian Bay, Lake Huron at the town of Parry Sound. The river's name comes from the Ojibwe word ziigwan, meaning "spring".

Parry Sound is a town in Ontario, Canada, located on the eastern shore of the sound after which it is named. Parry Sound is located 160 km (99 mi) south of Sudbury and 225 km (140 mi) north of Toronto. It is a single tier government located in the territorial District of Parry Sound which has no second tier County, Regional or District level of government. Parry Sound is a popular cottage country region for Southern Ontario residents. It also has the world's deepest natural freshwater port.