The mangrove whistler (Pachycephala cinerea) is a species of bird in the family Pachycephalidae found in South-east Asia.
Alternate names for the mangrove whistler include the grey thickhead and white-bellied whistler. The latter name should not be confused with the species of the same name, Pachycephala leucogastra. Formerly, both the green-backed and white-vented whistlers were considered to be subspecies of the mangrove whistler.