The taxonomic status of the two Japanese species of the spider genus Cybaeus L. Koch, 1868, viz., C. communis Yaginuma, 1972 and C. maculosus Yaginuma, 1972, is revisited on the basis of male and female specimens, which were collected from each type locality and the adjacent areas, along with the holotypes of both species. Mitochondrial cytochrome c oxidase subunit I and nuclear internal transcribed spacer 1 sequence data confirmed that C. communis and C. maculosus are conspecific, and C. maculosus is synonymized with C. communis. The obtained molecular phylogenies corroborate the monophyly of C.