Japanese macaques, Macaca fuscata (Gray, 1870), are systematically reviewed, based on examination of 1264 specimens, survey of relevant literature, and observation of natural populations. This review includes analyses of external and cranial characters, molecular biology and genetics, and parasites. Information also is presented concerning natural history, reproduction, fossils, and taxonomic history. Concerning the evolutionary history of M. fuscata, available evidence suggests that this species is derived from a M. mulatta–like population that dispersed to the Japanese archipelago during one or two glacial intervals of sea-level depression, ca. 0.63–0.43 million years ago (Ma), via a now-submerged dry-land connection between the Korean Peninsula and the Kyushu–West Honshu area. In an appendix, an annotated gazetteer lists 1347 localities at which M. fuscata has been collected or observed.