Mount Gambier is the second most populated city in South Australia, with a population of 25,591 as of the 2021 census. The city is located on the slopes of Mount Gambier, a volcano in the south east of the state, about 450 kilometres (280 mi) south-east of the capital Adelaide and just 17 kilometres (11 mi) from the Victorian border. The traditional owners of the area are the Bungandidj people. Mount Gambier is the most important settlement in the Limestone Coast region and the seat of government for both the City of Mount Gambier and the District Council of Grant.