The Crowsnest River is a tributary to the Oldman River in southwestern Alberta, Canada. From its source in Crowsnest Lake at an elevation of about 1,357 m (4,452 ft) in the Canadian Rockies, it meanders eastward through the Municipality of Crowsnest Pass and the Frank Slide. It passes into the foothills near Burmis and reaches the western margin of the Alberta plains near Lundbreck.