Signy Island is a small subantarctic island in the South Orkney Islands of Antarctica. It was named by the Norwegian whaler Petter Sørlle (1884–1933) after his wife, Signy Therese.

The South Orkney Islands are a group of islands in the Southern Ocean, about 604 km (375 mi) north-east of the tip of the Antarctic Peninsula and 844 km (524 mi) south-west of South Georgia Island. They have a total area of about 620 km2 (240 sq mi). The islands are claimed both by Britain, and by Argentina as part of Argentine Antarctica. Under the 1959 Antarctic Treaty, sovereignty claims are held in abeyance.