South Georgia and the South Sandwich Islands (SGSSI) is a British overseas territory in the southern Atlantic Ocean. It is a remote and inhospitable collection of islands, consisting of South Georgia – which measures approximately 106 miles (171 km) by 18 miles (29 km) and is by far the largest island in the territory – and a chain of smaller islands known as the South Sandwich Islands lying about 400 miles (640 km) to the south-east. There is no native population on any of the islands, and the only present inhabitants are the British Government Officer, Deputy Postmaster, scientists, and support staff from the British Antarctic Survey who maintain scientific bases at Bird Island and at the capital, King Edward Point, as well as museum staff at nearby Grytviken.

South Georgia and the South Sandwich Islands are rugged and mountainous. At higher elevations the islands are permanently covered with ice and snow. The South Georgia Group lies about 1,390 kilometres (864 mi) east-southeast of the Falkland Islands. It comprises South Georgia Island itself (by far the largest island in the territory), along with the islands that immediately surround it and some remote and isolated islets to the west and east-southeast. It has a total land area of 3,756 square kilometres (1,450 sq mi), including satellite islands (but excluding the South Sandwich Islands which form a separate island group). South Georgia Island, also called Pepys Island has an area of 3,528 km². It is mountainous and largely barren. Eleven peaks rise to over 2,000 metres (6,562 ft) high, their slopes furrowed with deep gorges filled with glaciers (Fortuna Glacier being the largest). The highest peak is Mount Paget in the Allardyce Range at 2,934 metres (9,626 ft).

Geologically, the island consists of gneiss and argillaceous schists, with no trace of fossils, showing that the island is, like the Falkland Islands, a surviving fragment of some greater land-mass now vanished, most probably indicating a former extension of the Andean system.