Janus Island is a rocky island 0.32 km (0.2 mi) long, lying 0.8 km (0.5 mi) south of Litchfield Island, off the southwest coast of Anvers Island in the Palmer Archipelago. Janus Island is located at (64°47′S64°06′W). Janus Island is the southernmost of the islands on the west side of the entrance to Arthur Harbor.