A new species of the African catfish subfamily Doumeinae of the family Amphiliidae is described from collections made in the Dimonika Biosphere Reserve in the eastern portion of the Republic of the Congo. The species, assignable to the genus Doumea, has the smallest known maximum length of the nine species of that genus. The new species is readily distinguishable from its congeners in having a relatively low number of pectoral-fin rays, vertebrae, and ribs and several morphometric features, especially those involving the caudal peduncle.