The genus Alloclemensia n.gen. (type-species: Alloclemensia maculata n.sp.), with four species in the Palaearctic region and one species in the Nearctic region, is described and its species are revised. The genus comprises five species: mesospilella (Herrich-Schäffer) [= trimaculella (Herrich-Schäffer)], devotella (Rebel) [= muchei (Soffner), n.syn.] and three new species: americana from North America and unifasciata and maculata from Japan. The monophyly of the genus is demonstrated and the primary dichotomy within the genus is considered to lie between the two western Palaearctic species plus the North American species and the two eastern Palaearctic species. Keys to the species are provided and all species and their genitalia are described and illustrated. Two new combinations and one new synonymy are established and two lectotypes are designated.