Pethia reval, the red-finned barb, is a species of cyprinid fish endemic to Sri Lanka. This species can reach a length of 3.4 centimetres (1.3 in) SL.

Congener, Pethia cumingii, also a Sri Lankan endemic, has long been presumed to be dichromatic with some populations exhibiting yellow fins and others displaying red fins. In 2008, the red-finned populations were elevated to the status of species and given the name, Pethia reval, while the yellow-finned form remains P. cumingii. It is P. reval, the red-finned species, that has been kept most frequently by aquarists since the 1930s though identified as P. cumingii throughout the aquarium literature and aquarium trade until recently.