Mount Gambier is the second most populated city in South Australia, with an estimated urban population of 33,233 as of 2021. 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.

South Australia is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of 984,321 square kilometres (380,048 sq mi), it is the fourth-largest of Australia's states and territories by area, and second smallest state by population. It has a total of 1.8 million people. Its population is the second most highly centralised in Australia, after Western Australia, with more than 77 percent of South Australians living in the capital Adelaide, or its environs. Other population centres in the state are relatively small; Mount Gambier, the second-largest centre, has a population of 26,878.