The Burnside River is a river in the Canadian terrirory of Nunavut. It has its headwaters at Contwoyto Lake (66°2′36″N111°14′33″W), flows across the Precambrian Shield's Contwoyto Plateau, flows through isolated and rugged tundra, into Lake Kathawachaga, and through the Wilberforce Hills region. Before emptying into Bathurst Inlet on the Arctic Ocean, the Mara River (Nunavut) empties into the Burnside River.