A new genus of Xanthopygina (Coleoptera: Staphylinidae: Staphylinini) is described here as Zackfalinus, new genus and includes 20 new species: Z. abothros, Z. agrammos, Z. alturas, Z. andersoni, Z. antennatus, Z. bierigi, Z. brzoskai, Z. carinatus, Z. erythrocephalos, Z. hardestae, Z. kitrinos, Z. kokkinos, Z. lamperos, Z. leptophallos, Z. limonus, Z. napus, Z. stenocephalos, Z. surinamus, Z. tricolor, and Z. ziegleri. The antennae in Zackfalinus are sexually dimorphic, with males having an elongate antennomere 11. An identification key, distribution maps, and illustrations of structural features are provided for the identification of species. Parsimony and Bayesian phylogenetic analyses of two outgroup taxa and 19 ingroup taxa were conducted based on 24 morphological characters. The consensus trees were only partly resolved but the results supported the monophyly of Zackfalinus with high bootstrap values and posterior probabilities.