The Rainy River, the Pigeon River, Lake Superior, the St. Marys River, Lake Huron, the St. Clair River, Lake St. Clair, the Detroit River, Lake Erie, the Niagara River, Lake Ontario are in Ontario.
Lake Ontario is one of the five Great Lakes of North America
 A French map produced in 1712 (currently in the Canadian Museum of History), created by military engineer Jean-Baptiste de Couagne, identified Lake Ontario as "Lac Frontenac" named after Louis de Buade, Comte de Frontenac et de Palluau

