Brock Island is one of the uninhabited members of the Queen Elizabeth Islands of the Arctic Archipelago located in the Northwest Territories, Canada. Located at 77°51'N 114°27'W, it measures 764 km2 in size and lies close to Mackenzie King Island. The first known sighting of the island by a European was by Vilhjalmur Stefansson in 1915 and it was later named for Reginald W. Brock, Dean of Applied Science at the University of British Columbia.