Ameripassalus, gen. nov., is described as the first genus of Passalini with a distribution restricted to Mesoamerica. The species include A. guatemalensis (Kaup, 1869), comb. nov. from Passalus Fabricius, A. difficilis, sp. nov. and A. tamaulipensis, sp. nov. from Mexico, and A. jacki, sp. nov. and A. nigritus, sp. nov. from Guatemala. A matrix of 46 morphological characters, including the species from Ameripassalus, gen. nov. and 13 species of the genera Paxillus MacLeay, Ptichopus Kaup, Heliscus Zang, Veturius Kaup, Spasalus Kaup, Passipassalus Fonseca & Reyes-Castillo, Passalus Fabricius and Leptaulax Kaup were analysed. Only a single most parsimonious tree was found; in this Ameripassalus is retrieved as a monophyletic group. Ameripassalus difficilis, sp. nov. is shown as the sister group of the rest of the species in the genus. The species with the southernmost distribution (A. guatemalensis (A. nigritus, sp. nov.   A. jacki, sp. nov.)) form a nested clade within the species with the northernmost distribution. Keys to identify adults of the genera of Passalini and to the species of Ameripassalus are provided.