McMullin Island () is a rocky island, 0.3 nautical miles (0.6 km) long, lying between Shirley and Kilby Islands in the south part of the entrance of Newcomb Bay, in the Windmill Islands. First mapped from air photos taken by U.S. Navy Operation Highjump and Operation Windmill in 1947 and 1948. Named by the Advisory Committee on Antarctic Names (US-ACAN) for John P. McMullin, air crewman with U.S. Navy Operation Windmill which established astronomical control in the area in January 1948.
This article incorporates public domain material from the United States Geological Survey document "McMullin Island" (content from the Geographic Names Information System).