Mount Barker is a city in South Australia. Located approximately 33 kilometres (21 miles) from the Adelaide city centre, it is home to 21,554 residents (2021). It is the seat of the District Council of Mount Barker, the largest town in the Adelaide Hills, Part of Greater Adelaide, as well as one of the fastest-growing areas in the state.

In 2021, Mount Barker was 51.8% female, and 48.2% male, compared with the national averages of 50.7% female and 49.3% male. Mount Barker had an average population age of 37, compared to the national average of 38. 47.4% of residents were married, compared to the national average of 46.5%.

The main route to Adelaide is via the South Eastern Freeway, which is used as a commuter road. The interchange at the western side of the town was built when the freeway was built in the 1970s. An additional interchange was opened in 2016 at the eastern side of the town.