Grinder Island () is one of the ice-covered islands in Marshall Archipelago, located within Sulzberger Ice Shelf, coastal Marie Byrd Land. The island is 7 nautical miles (13 km) long and 1 nautical mile (1.9 km) wide and lies 13 nautical miles (24 km) southwest of Steventon Island. Mapped by United States Geological Survey (USGS) from surveys and U.S. Navy air photos, 1959-65. Named by Advisory Committee on Antarctic Names (US-ACAN) for Harry W. Grinder, aviation structural mechanic, U.S. Navy, of McMurdo Station, 1967.
This article incorporates public domain material from the United States Geological Survey document "Grinder Island" (content from the Geographic Names Information System).