Mount Torrens (34°52′S 138°57′E) is a town in the eastern Adelaide Hills region of South Australia, 46 kilometres east-north-east of the state capital, Adelaide and 8 km east of Lobethal along the Onkaparinga River. It is located in the Adelaide Hills Council local government area. At the 2006 census, Mount Torrens had a population of 337.
The Indigenous name for the mount is unknown. The first Europeans to discover and ascend it, on 25 January 1838, were the exploration party of Dr. George Imlay and John Hill, but they did not name it.
The mount (and nearby town) was named later after Colonel Robert Torrens, one of South Australia's founding fathers, apparently in the mistaken belief that the Angas Creek which flows down the hill was the source of the Torrens River.
The town was developed by the Dunn family in the early 1840s. Then known as Barton Springs, it incorporated a farmhouse, smithy, stables and the Cornish Arms Inn. The town proper was laid out in 1853, and it served the Murray River trade at Mannum as well as a nearby copper mine. A small gold deposit was discovered in 1870, but by World War I, the town's importance had diminished, and the town that stands today is virtually unchanged since that time.
At the ABS 2001 census, Mount Torrens had a population of 319 people living in 120 dwellings.
Mount Torrens has a football club, hotel and general store, as well as several historical buildings.
Mount Torrens was served by the Mount Pleasant railway line from 1918 to 1953.