ABSTRACT A multigene phylogeny of the Inocybe alienospora group is presented based on analyses of ITS, 28S, and rpb2 nucleotide data. Four major subclades and three additional independent lineages were identified in the I. alienospora group. Two species with superficial similarities with the I. alienospora group, viz, I. multicoronata and I. elata, however, were not nested within the I. alienospora group. Inocybe sect. Leptocybe is proposed to accommodate the I. alienospora group in a more formal classification system. As such, sect. Leptocybe now includes 12 documented species and seven new species described in this work. The seven new species include I. aprica sp. nov., I. casuarinoides sp. nov. I. haikouensis sp. nov., three species associated with Casuarina from tropical China; also I. heteromorpha, a species associated with fagaceous trees from tropical China; and I. aurescens sp. nov., I. juji sp. nov., and I. peppa sp. nov., three species associated with fagaceous trees from subtropical China. In addition, new geographical data for I. carpinicola and I. acutata are reported. The East Asian species I. acutata and the neotropical species I. lasseri were confirmed as members of sect. Leptocybe. A key to the 19 species in sect. Leptocybe is also provided.