McCarthy Island is an island 2 nautical miles (4 km) long, lying just northeast of Fold Island, off the coast of Kemp Land, Antarctica. It was mapped as part of Fold Island (Foldoya) by Norwegian cartographers from air photos taken by the Lars Christensen Expedition, 1936–37, but was identified as a separate island by an Australian National Antarctic Research Expeditions (ANARE) geological party in 1961. The island was named by the Antarctic Names Committee of Australia for W.R.