The cleftbelly trevally (Atropus atropos) (also known as the cleftbelly kingfish, Kuweh trevally and thin crevalle) is a species of tropical marine fish of the jack family, Carangidae. The species inhabits coastal waters throughout the Indo-West Pacific region from South Africa in the west to Japan in the east, often found near the water's surface. The cleftbelly trevally is the only member of the genus Atropus and is distinguished by a number of anatomical characteristics, with a deep median groove in the belly giving the species its common name. It is not a large fish, growing to a maximum recorded length of 26.5 cm. Cleftbelly trevally are predatory fish, taking a variety of small crustaceans and fish. The species is of minor importance to fisheries throughout its range.