Zimmerman Island is a mainly ice-free island 0.4 miles (0.6 km) southeast of Werlein Island 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 R. Zimmerman, meteorologist and member of the Wilkes Station party of 1958.