Daftar spesies mamalia di Jepang
Ordo: Artiodactyla (hewan berkuku genap)

Wild boar (Japanese boar, Ryūkyū boar), Reeves's muntjac, sika deer, Japanese serow, North Pacific right whale, common minke whale, sei whale, Bryde's whale, Omura's whale, blue whale, fin whale, humpback whale, grey whale, beluga whale, harbour porpoise, Dall's porpoise, sperm whale, pygmy sperm whale, dwarf sperm whale, Cuvier's beaked whale, Baird's beaked whale, Indo-Pacific beaked whale, Blainville's beaked whale, rough-toothed dolphin, Indo-Pacific bottlenose dolphin, common bottlenose dolphin, pantropical spotted dolphin, striped dolphin, spinner dolphin, long-beaked common dolphin, short-beaked common dolphin, Fraser's dolphin, Pacific white-sided dolphin, northern right whale dolphin, Risso's dolphin, melon-headed whale, pygmy killer whale, false killer whale, orca, short-finned pilot whale
Ungulata berjari genap adalah ungulata yang berat badannya ditanggung secara seimbang oleh jari kaki ketiga dan keempat, dan bukan sebagian besar atau sepenuhnya ditanggung oleh jari kaki ketiga seperti pada perissodactyl . Ada sekitar 220 spesies artiodactyl darat, termasuk banyak yang memiliki kepentingan ekonomi besar bagi manusia. Artiodactyla juga mencakup infraordo Cetacea, yang meliputi paus, lumba-lumba, dan pesut. Cetacea merupakan mamalia yang paling mampu beradaptasi dengan kehidupan akuatik, dengan tubuh berbentuk gelendong dan hampir tidak berbulu, dilindungi oleh lapisan lemak tebal, serta kaki depan dan ekor yang dimodifikasi untuk memberikan tenaga penggerak di bawah air.
Family: Suidae (pigs)
Subfamily: Suinae
Genus: Sus
Wild boar, Sus scrofa LC IUCN
Japanese boar, S. s. leucomystax (Honshū south from Fukushima, Shikoku, Kyūshū, Awaji Island)
Ryūkyū boar [ja] S. s. riukiuanus (Ryūkyū Islands; half as massive as Sus scrofa leucomystax)
Family: Cervidae (deer)
Subfamily: Cervinae
Genus: Muntiacus
Reeves's muntjac, Muntiacus reevesi LC IUCN (introduced; southern Chiba and Izu Ōshima)
Genus: Rusa
Sambar deer, Rusa unicolor VU IUCN
Bonin sambar, R. u. boninensis (EX)
Genus: Cervus
Sika deer, Cervus nippon LC IUCN (widely distributed; Kerama deer and their habitat, and the deer of Nara, are Natural Monuments)
Northern Honshu sika deer, C. n. aplodontus
Honshu sika deer, C. n. centralis
Kerama deer, C. n. keramae
Mageshima deer, C. n. mageshimae
C. n. nippon
Tsushima deer, C. n. pulchellus
Yakushima deer [ja], C. n. yakushimae
Yezo sika deer, C. n. yesoensis
Family: Bovidae (cattle, antelope, sheep, goats)
Subfamily: Caprinae
Genus: Capricornis
Japanese serow, Capricornis crispus LC IUCN (endemic; Honshū, Shikoku, Kyūshū; Special Natural Monument)
Infraorder: Cetacea
Parvorder: Mysticeti
Family: Balaenidae
Genus: Eubalaena
North Pacific right whale, Eubalaena japonica EN IUCN
Family: Balaenopteridae
Subfamily: Balaenopterinae
Genus: Balaenoptera
Common minke whale, Balaenoptera acutorostrata LC IUCN
Sei whale, Balaenoptera borealis EN IUCN
Bryde's whale, Balaenoptera edeni LC IUCN
Omura's whale, Balaenoptera omurai DD IUCN
Blue whale, Balaenoptera musculus EN IUCN (no recent records in neighbouring waters)
Fin whale, Balaenoptera physalus VU IUCN
Subfamily: Megapterinae
Genus: Megaptera
Humpback whale, Megaptera novaeangliae LC IUCN (regular sightings in the Ogasawara Islands and Okinawa)
Family: Eschrichtiidae
Genus: Eschrichtius
Grey whale, Eschrichtius robustus LC IUCN (occasional sightings of western subpopulation EN IUCN)
Parvorder: Odontoceti
Superfamily: Platanistoidea
Family: Monodontidae
Genus: Delphinapterus
Beluga, Delphinapterus leucas LC IUCN vagrant
Family: Phocoenidae
Genus: Neophocaena
Narrow-ridged finless porpoise, Neophocaena asiaeorientalis EN IUCN
Genus: Phocoena
Harbour porpoise, Phocoena phocoena LC IUCN
Genus: Phocoenoides
Dall's porpoise, Phocoenoides dalli LC IUCN
Family: Physeteridae
Genus: Physeter
Sperm whale, Physeter macrocephalus VU IUCN
Family: Kogiidae
Genus: Kogia
Pygmy sperm whale, Kogia breviceps LC IUCN
Dwarf sperm whale, Kogia sima LC IUCN
Family: Ziphidae
Genus: Ziphius
Cuvier's beaked whale, Ziphius cavirostris LC IUCN
Genus: Berardius
Baird's beaked whale, Berardius bairdii LC IUCN
Sato's beaked whale, Berardius minimus NT IUCN
Subfamily: Hyperoodontinae
Genus: Indopacetus
Indo-Pacific beaked whale, Indopacetus pacificus LC IUCN
Genus: Mesoplodon
Hubbs' beaked whale, Mesoplodon carlhubbsi DD IUCN
Blainville's beaked whale, Mesoplodon densirostris LC IUCN*
Ginkgo-toothed beaked whale, Mesoplodon ginkgodens DD IUCN
Stejneger's beaked whale, Mesoplodon stejnegeri NT IUCN
Family: Delphinidae (marine dolphins)
Genus: Steno
Rough-toothed dolphin, Steno bredanensis LC IUCN
Genus: Tursiops
Indo-Pacific bottlenose dolphin, Tursiops aduncus NT IUCN
Common bottlenose dolphin, Tursiops truncatus LC IUCN
Genus: Stenella
Pantropical spotted dolphin, Stenella attenuata LC IUCN
Striped dolphin, Stenella coeruleoalba LC IUCN
Spinner dolphin, Stenella longirostris LC IUCN (common around the Ogasawara Islands)
Genus: Delphinus
Long-beaked common dolphin, Delphinus capensis LC IUCN
Short-beaked common dolphin, Delphinus delphis LC IUCN
Genus: Lagenodelphis
Fraser's dolphin, Lagenodelphis hosei LC IUCN
Genus: Sagmatias
Pacific white-sided dolphin, Sagmatias obliquidens LC IUCN
Genus: Lissodelphis
Northern right whale dolphin, Lissodelphis borealis LC IUCN
Genus: Grampus
Risso's dolphin, Grampus griseus LC IUCN
Genus: Peponocephala
Melon-headed whale, Peponocephala electra LC IUCN
Genus: Feresa
Pygmy killer whale, Feresa attenuata LC IUCN
Genus: Pseudorca
False killer whale, Pseudorca crassidens NT IUCN
Genus: Orcinus
Orca, Orcinus orca DD IUCN
Genus: Globicephala
Short-finned pilot whale, Globicephala macrorhynchus LC IUCN