Mount Bonython, Mountain summit in Mount Lofty Ranges, South Australia.

Mount Bonython is a summit in the Mount Lofty Ranges that reaches 677 meters above sea level. The peak holds a telecommunications tower and offers views across the Adelaide Hills region and surroundings.

Mount Bonython was long known as Little Mount before being renamed after Sir John Langdon Bonython, the South Australian newspaper proprietor and politician. The change distinguished it from its taller neighbour, Mount Lofty, about a kilometre to the south.

In Kaurna mythology, the ancestor-creator Nganno was wounded in battle, lay down to die and formed the Mount Lofty Ranges. Yurrebilla is the Kaurna name for the twin hills Mount Lofty and Mount Bonython, understood as Nganno's ears; the Greater Mount Lofty Parklands take their name from it.

Mount Bonython lies about 11 km east of Adelaide in the Adelaide Hills, roughly a kilometre north of Mount Lofty, whose summit is some 50 m higher. The Telstra NextG tower stands on the summit itself. The area receives about 729 mm of rain a year, with June the wettest month and December the driest.

The summit carries a Telstra NextG telecommunications tower, a detail easy to miss from below. The Kaurna name Yurrebilla refers to Mount Lofty and Mount Bonython together as the ears of the ancestor-creator Nganno.