The Bloodvein River is a river in Canada. It flows west from its headwaters in Red Lake in northwest Ontario to the east side of Lake Winnipeg in Manitoba through the boreal forests of the Canadian Shield. It is around 300 kilometres (190 mi) long. Lakes along its length include Knox Lake, Pipestone Lake and Artery Lake. The Bloodvein River became Manitoba's first Canadian Heritage River in 1987. For most of its length, the river is within Atikaki Provincial Park in Manitoba and the Woodland Caribou Provincial Park in Ontario.It became part of a United Nations World Heritage Site in 2018.