South Georgia has an area of 1,450 square miles (3,756 square km). It is 100 miles (160 km) long and 20 miles (32 km) wide and rises to Mount Paget (9,625 feet 【2,934 metres】). The island's bleak Antarctic climate, with perpetual snow covering three-fourths of the island, supports only hardy grasses and other tundra plants. Reindeer were introduced shortly after 1900 and have survived. Marine life is abundant offshore, and there are a number of species of penguins and seals. Whaling ceased in the area in 1965, but commercial fishing vessels still harvest Patagonian toothfish, icefish, and Antarctic krill in the islands' territorial waters. A small number of scientists and support personnel maintain British Antarctic Survey stations at Grytviken on King Edward Point and at Bird Island, off the northwest tip of the island, and constitute the island's only inhabitants.

Capt. James Cook (Cook, James) visited and claimed South Georgia for Britain in 1775. It subsequently was made a dependency of the Falkland Islands. The island periodically served as a base for whaling and scientific expeditions during the 19th century, and Norwegian whalers founded a commercial outpost at Grytviken in 1904. Great Britain formally annexed South Georgia and the South Sandwich Islands in 1908. The British explorer Sir Ernest Shackleton (Shackleton, Sir Ernest Henry) first crossed South Georgia Island in 1916 while in search of aid for his ill-fated trans-Antarctic expedition. He later died on the island and was buried at Grytviken. Argentina made a territorial claim to South Georgia in 1927.

Britain began establishing research stations on the island in 1945, but it was not until 1964–65 that further explorations of the island's interior were made, including the first ascent of Mount Paget. The island was the site of military occupation as part of Argentina's unsuccessful attempt to annex the Falkland Islands and their dependencies during the Falkland Islands War in 1982. A British garrison was established on the island after the war but was decommissioned in 2001. South Georgia and the South Sandwich Islands became a British overseas territory in 1985. A commissioner, who is also the governor of the Falkland Islands, oversees the territory. In 1993 Britain extended the territory's exclusive fishing zone from 12 to 200 nautical miles (22 to 370 km). Cruise ships make regular visits to the island. The South Georgia Museum, located in the former home of a whaling-station manager, was established in 1992 and has exhibits on whaling, maritime and natural history, and Shackleton memorabilia, among other themes.