The South Orkney Islands are a group of islands in the Southern Ocean, about 604 kilometres north-east of the tip of the Antarctic Peninsula and 844 kilometres south-west of South Georgia Island. They have a total area of about 620 square kilometres. The islands are claimed both by Britain (as part of the British Antarctic Territory since 1962, previously as a Falkland Islands Dependency), and by Argentina as part of Argentine Antarctica. Under the 1959 Antarctic Treaty, sovereignty claims are held in abeyance.

Britain and Argentina both maintain bases on the islands. The Argentine base, Orcadas, established 1904, is sited on Laurie Island. The 11 buildings of the Argentine station house up to 45 people during the summer, and an average of 14 during winter. The British Antarctic Survey base, Signy Research Station, is located on Signy Island and was established in 1947. Initially operated year-round, since 1995/6 the Signy Research Station has been open only from November to April each year (southern hemisphere summer).

Apart from personnel at the bases, there are no permanent inhabitants on the islands.

The South Orkney Islands were discovered in 1821 by two sealers, the American Nathaniel Brown Palmer and the British George Powell. The islands were originally named Powell's Group, with the main island named Coronation Island as it was the year of the coronation of King George IV. In 1823, James Weddell visited the islands, gave the archipelago its present name (after the Orkney Islands in the north of Scotland) and also renamed some of the islands. The South Orkney Islands are located at roughly the same latitude south as the Orkney Islands are north (60°S vs 59°N), although it is not known if this was a factor behind the naming of the islands. Similarly the South Shetland Islands, discovered in 1819 by William Smith, are roughly the same latitude south as the Shetland Islands are north (62°S vs 60°N).

Subsequently, the South Orkney Islands were frequently visited by sealers and whalers, but no thorough survey was done until the expedition of William Speirs Bruce on the Scotia in 1903, which overwintered at Laurie Island. Bruce surveyed the islands, reverted some of Weddell's name changes, and established a meteorological station, which was sold to the Argentine Government upon his departure in 1904. This base, renamed Orcadas in 1951, is still in operation today and is thus the oldest research station continuously staffed in the Antarctic.