Little Cornwallis Island is one of the Canadian arctic islands in Nunavut, Canada. It is located at 75°30'N 96°30'W, between Cornwallis Island and Bathurst Island, and measures 412 square kilometers. It is uninhabited.

Little Cornwallis Island was noteworthy as home to Polaris Mine, the most poleward base-metal mine in the world. In 1960 a vast concentration of zinc and lead was discovered on the island during mapping for oil permits. Cominco acquired land in the area and a gravity survey in 1970 detected a large anomaly. By 1973 surface drilling and underground development had outlined the Polaris ore body and defined reserves of about 25 million tons grading approximately 14% zinc and 4% lead. A mining facility was constructed on a barge at Trois-Rivières, Quebec and towed to the island in late 1980. Production commenced in 1982. The mile-long gravel runway allowed aircraft as large as the Boeing 727 and Boeing 737 to service the mine. The mine was closed in August 2002 as forecast due to depletion of the ore body. During its history about 20 million tonnes of ore were extracted. A two-year, $53 million decommissioning and reclamation program was completed in September 2004.