Janus Island is a rocky island 0.2 miles long, lying 0.5 miles south of Litchfield Island, off the southwest coast of Anvers Island in the Palmer Archipelago. Janus Island is located at . Janus Island is the southernmost of the islands on the west side of the entrance to Arthur Harbor. Janus Island was named by the United Kingdom Antarctic Place-names Committee (UK-APC) following survey by the Falkland Islands Dependencies Survey (FIDS) in 1955. The name Janus Island, for the ancient Latin deity Janus who was guardian of gates, arose because of the position of the island at the entrance to Arthur Harbor.
