| South Twin Island | |
| Pushpin Map: | Canada Nunavut#Canada |
| Native Name Link: | Inuktitut |
| Location: | Northern Canada |
| Coordinates: | 53.1667°N -129°W |
| Archipelago: | Arctic Archipelago |
| Country: | Canada |
| Country Admin Divisions Title: | Territory |
| Country Admin Divisions: | Nunavut |
| Country Admin Divisions Title 1: | Region |
| Country Admin Divisions 1: | Qikiqtaaluk |
| Population: | Uninhabited |
South Twin Island is an uninhabited Arctic island located east of Akimiski Island toward the center of James Bay. The larger, similarly shaped, North Twin Island is located approximately 10 km northwest. South Twin Island has mossier tundra and fewer trees than North Twin Island. The two islands are referred to as the Twin Islands and are part of the Qikiqtaaluk Region of the Canadian territory of Nunavut.
South Twin Island is an important breeding site for Canada geese and semipalmated plovers.[1]