Mackenzie King Island is one of the Queen Elizabeth Islands north of Canada. It lies north of Melville Island and south of Borden Island, and like them is divided. Most of the island is in Northwest Territories, while a few of its easternmost extremities lie in Nunavut.
Mackenzie King has an area of , making it the 115th largest island in the world, and Canada's 26th largest island.
The low-lying island was reached by Vilhjalmur Stefansson
in 1915, and later named for William Lyon Mackenzie King
- Vilks, G. Foraminiferal Study of East Bay, Mackenzie King Island, District of Franklin (Polar Continental Shelf Project). [Ottawa]: Dept. of Mines and Technical Surveys, 1964.