As of October 2026, the International Union for Conservation of Nature (IUCN) listed 236 critically endangered mammalian species, including 29 which are tagged as possibly extinct. Of all evaluated mammalian species, 3.9% are listed as critically endangered. The IUCN also lists 59 mammalian subspecies as critically endangered.
Of the subpopulations of mammals evaluated by the IUCN, 22 species subpopulations have been assessed as critically endangered.
Additionally 773 mammalian species (12.8% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. While the category of data deficient indicates that no assessment of extinction risk has been made for the taxa, the IUCN notes that it may be appropriate to give them "the same degree of attention as threatened taxa, at least until their status can be assessed".
This is a complete list of critically endangered mammalian species and subspecies evaluated by the IUCN. Species considered possibly extinct by the IUCN are marked as such. Species and subspecies which have critically endangered subpopulations (or stocks) are indicated. Where possible common names for taxa are given while links point to the scientific name used by the IUCN.
Primates There are 88 species and 37 subspecies of primates assessed as critically endangered.
Gibbons
Species
Great apes
Species
Subspecies
Lemurs
Species
Subspecies
Sportive lemurs Ahmanson's sportive lemur Holland's sportive lemur Mittermeier's sportive lemur Red-tailed sportive lemur
Tarsiers
Species Siau Island tarsier Subspecies Natuna Islands tarsier
Old World monkeys
Species
Subspecies
New World monkeys
Species
Subspecies
Lorisoidea Javan slow loris Bangka slow loris (possibly extinct) Mount Kenya potto (ssp. stockleyi, possibly extinct)
Odd-toed ungulates
Species
Subspecies
Cetartiodactyls Cetartiodactyla includes dolphins, whales and even-toed ungulates. There are 16 species, 12 subspecies, and 15 subpopulations of cetartiodactyl assessed as critically endangered. Non-cetacean even-toed ungulates
Species
Subspecies
Cetaceans
Species Baiji (possibly extinct) Vaquita Rice's whale North Atlantic right whale Atlantic humpback dolphin Subspecies
Subpopulations
Marsupials
Carnivora
Species
Subspecies
Subpopulations
Eulipotyphla
Lagomorpha
Rodents There are 64 species and 1 subspecies of rodent assessed as critically endangered.
Hystricomorpha
Myomorpha There are 37 species in Myomorpha assessed as critically endangered.
Murids
Cricetids
Nesomyids Mount Kahuzi climbing mouse
Sminthids Severtzov's birch mouse (possibly extinct)
Castorimorpha
Species
Subspecies Alcorn's pocket gopher
Sciuromorpha Namdapha flying squirrel Vancouver Island marmot
Bats
Other mammals
Species
Subspecies Sumatran elephant Subpopulations Juliana's golden mole (1 subpopulation)
See also Lists of IUCN Red List critically endangered species List of least concern mammals List of near threatened mammals List of vulnerable mammals List of endangered mammals List of recently extinct mammals List of data deficient mammals
References