The Red Deer River is a river in Alberta and a small portion of Saskatchewan, Canada. It is a major tributary of the South Saskatchewan River and is part of the larger Saskatchewan/ Nelson system that empties into Hudson Bay. The river has a total length of 724 km and a drainage area of 45,100 km2. Its mean discharge is 70 m3/s. The river is named for the translation of a native term for the river, wâwâskêsiw sîpiy, which means "elk river" in the Cree language.