Canada's longest rivers based on length

The longest river in Canada is the Mackenzie River in the Northwest Territories, measured at 4,240 kilometers in length, in comparison to the St. Lawrence River, spanning both Quebec and Ontario, which is 3,058 kilometers. In terms of discharge volume, the St. Lawrence River is considered the largest river, discharging some 9,850 cubic meters of water per second.

Mackenzie River

The Mackenzie River is not only the longest river in Canada, it is also considered the second longest river system in North America, and the twelfth longest river in the world. This river system travels through both the Yukon Territories and the Northwest Territories, ending at the Arctic Ocean. Most of the river runs through isolated tundra and forest regions and is considered one of the most undisturbed ecosystems in North America.

St. Lawrence River

The St. Lawrence is the third longest river in Canada and the river’s source comes from Lake Ontario. Its mouth is located at the Gulf of St. Lawrence and goes into the Atlantic Ocean. It has an important stake in history as one of the main routes into North America by European explorers as well as an important transportation channel that allows ships to travel up to the Lake Superior.