South Cinque Island or Ga-o-ta-koiis an uninhabited island in the Andaman Archipelago, between North Cinque Island (about 1 km to the north) and Passage Island (about 6 km to the south). It is a part of Mahatma Gandhi Marine National Park and of the Andaman and Nicobar Islands Union Territory of India.
The island is a popular destination for underwater diving and tourism. A new species of blenny, Alloblennius frondiculus was found in the surrounding waters.
South Cinque and North Cinque are sometimes considered to be a single Cinque Island.