Dot Island is a tiny island in the sub-Antarctic. It is 0.6 nautical miles (1.1 km) west of Tern Island in the south part of the Bay of Isles, South Georgia. It was first charted by Robert Cushman Murphy in 1912–13. It was surveyed in 1929–30 by Discovery Investigations personnel. They probably named it because of its size and small appearance on charts.