Adelaide Gaol is a former Australian prison located in the Park Lands of Adelaide, in the state of South Australia. The gaol was the first permanent one in South Australia and operated from 1841 until 1988. The Gaol is one of the two oldest buildings still standing in South Australia, the other being Government House which was built at the same time. The prison is now a museum, tourist attraction and function centre.

The Adelaide Park Lands comprise the figure-eight configuration of land, spanning both banks of the River Torrens between Hackney and Thebarton, which encloses and separates the City of Adelaide area from the surrounding suburbia of greater metropolitan Adelaide, the capital city of South Australia. They were laid out by Colonel William Light in his design for the city, and originally consisted of 2,300 acres (930 ha) "exclusive of 32 acres (13 ha) for a public cemetery". One copy of Light's plan shows areas for a cemetery and a Post and Telegraph Store on West Terrace, a small Government Domain and Barracks on the central part of North Terrace, a hospital on East Terrace, a Botanical Garden on the River Torrens west of North Adelaide, and a school and a storehouse south-west of North Adelaide.