Tanner Island () is the westernmost and largest of the Pickersgill Islands, rising to 145 m off the south coast of South Georgia. Named by United Kingdom Antarctic Place-Names Committee (UK-APC) for William G. Tanner, British Antarctic Survey (BAS) geologist, who worked on the island during the 1975-76 field season.
This article incorporates public domain material from the United States Geological Survey document "Tanner Island" (content from the Geographic Names Information System).