A town of Hindmarsh county, South Australia, at the foot of the mountain of the same name, 342 m. by rail E. of Adelaide. It has an extremely fine climate and is much frequented as a health resort in summer. It is the centre of a populous and fertile district producing quantities of fruit, wheat and dairy produce; important cattle sales are held weekly, and there are several engineering works, flour mills and tanneries in the town, which also is the seat of a wattle-bark industry. Pop. about 2000; but the inhabitants of the Mount Barker district number over 34,000.