The Cressbrook Dam is an earth-filled embankment dam across Cressbrook Creek, located north-east of Toowoomba in the locality of Biarra in the Somerset Region of Queensland, Australia. Completed in 1983, the resultant reservoir, Lake Cressbrook, is one of three storages used to supply potable water to Toowoomba and the surrounding region. The dam is operated by the Toowoomba Regional Council.
The dam is high and long. When full, the impounded reservoir, Lake Cressbrook, has a capacity of , of which are usable. The reservoir covers at an average depth of and draws from a catchment area.
The catchment contains Perseverance Dam, that also supplies potable water to Toowoomba, which is located upstream of Cressbrook Dam. Cooby Dam also supplies water to Toowoomba.
In 2022, it was suggested that a pumped-storage hydroelectric project be added to the dam, to generate / .
A Stocked Impoundment Permit is required to fish in the dam.