The Dandenong Ranges are a set of low mountain ranges in Victoria, Australia, approximately 35 km (22 mi) east of the state capital Melbourne. A minor branch of the Great Dividing Range, the Dandenongs consist mostly of rolling hills, rising to 633 m (2,077 ft) at Mount Dandenong, as well as steeply weathered valleys and gullies covered in thick temperate rainforest, predominantly of tall mountain ash trees and dense ferny undergrowth. The namesaked Dandenong Creek and most of its left-bank tributaries originate from headwaters in these mountain ranges. Two of Melbourne's most important storage reservoirs, the Cardinia and Silvan Reservoir, are also located within the Dandenongs.

The Dandenong Creek is an urban creek of the Port Phillip catchment, located in the eastern and south-eastern Greater Melbourne region of the Australian east coast state of Victoria. The creek descends approximately 550 metres (1,800 ft) over its course of 53 kilometres (33 mi) before joining the Eumemmerring Creek to form the Patterson River and eventually draining into the Beaumaris Bay.