Monarto is a locality in South Australia 16 kilometres (9.9 mi) west of the Murray River. It is north of the South Eastern Freeway between the Callington and Murray Bridge exits 63 km from Adelaide.
Most of the residents of Monarto run small hobby-like farms, raising cows, sheep and horses. Crops in the area include wheat, oats and barley.
In the late 1970s Monarto (or "New Murray Town") was proposed to be the site of a new satellite city of Adelaide. By the turn of the century the proposal had been completely abandoned.