Red River of the North, a river in the north-central United States and in Canada. It begins at the junction of the Otter Tail and Bois de Sioux rivers on the North Dakota-Minnesota border and flows northward 545 miles (880 km) to Lake Winnipeg, in Manitoba. The river drains parts of Minnesota, North Dakota, South Dakota, Manitoba, Ontario, and Saskatchewan. The Assiniboine is the chief tributary; Winnipeg, Manitoba, is the largest city on the river. Some of the richest soils and most productive wheat fields in North America are found in the valley of the river.

In Canada the Red River Valley was the site of the Red River Settlement, a farming colony, founded by Lord Selkirk, a Scotsman, in 1812. It was the first important agricultural settlement on the western plains of Canada and was the origin of Manitoba province. The Red River Rebellion took place here, 1869-70.