A new monotypic genus of Hoplojassini from French Guiana is proposed, described, and illustrated. Carinojassus gen. nov. differs from other genera of the tribe by the slightly produced crown; deeply transversely striated and strongly declivous pronotum; scutellum not extended posterior to the clavus apex of the forewing at rest and with the posterior half strongly keeled medially and elevated dorsally; and the apically rounded forewing.
Keywords: Hemiptera, Auchenorrhyncha, Carinojassus gen. nov., Hoplojassus, Nigrojassus, leafhoppers.