The Churchman Brook Dam is an earth-fill embankment dam approximately southeast of Perth, Western Australia in the City of Armadale. The reservoir serves as a source of potable water for Perth. The reservoir has a capacity of for a catchment area of .
The creation of the dam was announced in March 1923 by Premier James Mitchell. Along with Canning Dam and Wungong Dam, it formed part of the Hills Water Supply Scheme which was intended to rectify severe water shortages in metropolitan Perth. Its capacity was initially estimated at .
Construction of the dam commenced in 1923 and was completed in 1929; the resident engineer was Sir Russell John Dumas.
The dam was added to the City of Armadale's heritage list on 1 December 2008.