Dereel is an old gold mining town in the Western District of the Australian state of Victoria. At the 2011 census Dereel and the surrounding area had a population of 586 down from the 2006 population of 669. Dereel includes the area to the west known as Mount Mercer.
It is located on the Ballarat-Colac Road, 33 kilometres south of Ballarat and 70 kilometres north of Colac. There is no clearly defined town centre, though the Dereel Soldiers' Memorial Hall, located on Swamp Road, is commonly considered as the town centre.
The Dereel Post Office opened on 1 November 1868 and closed in 1971 and was located at the corner of the Colac-Ballarat road and Dereel-Rokewood Junction road.
Dereel includes a large wetlands area, referred to as the "Swamp" or "Lagoon". During the 1930's this swamp area was used as a race course.