| Order | Family | Genus | Specific Epithet | authority | common name | Sources (full citations given below this table) |
| Artiodactyla | Cervidae | Alces | americanus | (L.) | moose | |
| Artiodactyla | Cervidae | Odocoileus | virginianus | (Zimmermann) | white-tailed deer | |
| Carnivora | Canidae | Canis | latrans | Say | coyote | |
| Carnivora | Canidae | Urocyon | cinereoargenteus | (Schreber) | gray fox | Maine IF&W (3) |
| Carnivora | Canidae | Vulpes | vulpes | (L.) | red fox | Maine IF&W (3) |
| Carnivora | Felidae | Lynx | canadensis | Kerr | Canada lynx | Maine IF&W (4) |
| Carnivora | Felidae | Lynx | rufus | (Schreber) | bobcat | |
| Carnivora | Mephitidae | Mephitis | mephitis | (Schreber) | striped skunk | |
| Carnivora | Mustelidae | Lontra | canadensis | (Schreber) | river otter | |
| Carnivora | Mustelidae | Martes | americana | (Turton) | American marten | |
| Carnivora | Mustelidae | Martes | pennanti | (Erxleben) | fisher | |
| Carnivora | Mustelidae | Mustela | erminea | L. | short-tailed weasel | |
| Carnivora | Mustelidae | Mustela | frenata | Lichtenstein | long-tailed weasel | |
| Carnivora | Mustelidae | Neovison | vison | (Schreber) | mink | |
| Carnivora | Phocidae | Halichoerus | grypus | (Fabricius) | gray seal | |
| Carnivora | Phocidae | Phoca | vitulina | L. | harbor seal | |
| Carnivora | Procyonidae | Procyon | lotor | (L.) | common raccoon | |
| Carnivora | Ursidae | Ursus | americanus | Pallas | black bear | |
| Chiroptera | Vespertilionidae | Eptesicus | fuscus | (Beauvois) | big brown bat | Maine IF&W (1) |
| Chiroptera | Vespertilionidae | Lasionycteris | noctivagans | (LeConte) | silver-haired bat | Maine IF&W (1) |
| Chiroptera | Vespertilionidae | Lasiurus | borealis | (Müller) | eastern red bat | Maine IF&W (1) |
| Chiroptera | Vespertilionidae | Lasiurus | cinereus | (Beauvois) | hoary bat | Maine IF&W (1) |
| Chiroptera | Vespertilionidae | Myotis | keenii | (Merriam) | northern myotis | |
| Chiroptera | Vespertilionidae | Myotis | leibii | (Audubon and Bachman) | eastern small-footed bat | Maine IF&W (1) |
| Chiroptera | Vespertilionidae | Myotis | lucifugus | (LeConte) | little brown bat | Maine IF&W (1) |
| Chiroptera | Vespertilionidae | Myotis | septentrionalis | (Trouessart) | northern long-eared bat | Maine IF&W (1) |
| Chiroptera | Vespertilionidae | Myotis | sodalis | Miller and G. M. Allen | Indiana myotis | |
| Chiroptera | Vespertilionidae | Pipistrellus | subflavus | (F. Cuvier) | tri-colored bat | Maine IF&W (1) |
| Didelphimorphia | Didelphidae | Didelphis | virginiana | Kerr | Virginia opossum | Maine IF&W (2) |
| Eulipotyphia | Soricidae | Blarina | brevicauda | (Say) | northern short-tailed shrew | |
| Eulipotyphia | Soricidae | Sorex | cinereus | Kerr | masked shrew | |
| Eulipotyphia | Soricidae | Sorex | dispar | Batchelder | rock shrew | |
| Eulipotyphia | Soricidae | Sorex | fumeus | G. M. Miller | smoky shrew | |
| Eulipotyphia | Soricidae | Sorex | hoyi | Baird | pygmy shrew | |
| Eulipotyphia | Soricidae | Sorex | palustris | Richardson | American water shrew | |
| Eulipotyphia | Talpidae | Condylura | cristata | (L.) | star-nosed mole | |
| Eulipotyphia | Talpidae | Parascalops | breweri | (Bachman) | hairy-tailed mole | |
| Lagomorpha | Leporidae | Lepus | americanus | Erxleben | snowshoe hare | |
| Lagomorpha | Leporidae | Sylvilagus | transitionalis | (Bangs) | New England cottontail | |
| Rodentia | Castoridae | Castor | canadensis | Kuhl | American beaver | |
| Rodentia | Cricetidae | Microtus | chrotorrhinus | (Miller) | rock vole | |
| Rodentia | Cricetidae | Microtus | pennsylvanicus | (Ord) | meadow vole | |
| Rodentia | Cricetidae | Microtus | pinetorum | (Le Conte) | pine vole | |
| Rodentia | Cricetidae | Ondatra | zibethicus | (L.) | common muskrat | |
| Rodentia | Dipodidae | Napaeozapus | insignis | (Miller) | woodland jumping mouse | |
| Rodentia | Dipodidae | Zapus | hudsonius | (Zimmermann) | meadow jumping mouse | |
| Rodentia | Erethizontidae | Erethizon | dorsatum | (L.) | common porcupine | |
| Rodentia | Muridae | Clethrionomys | gapperi | (Vigors) | southern red-backed vole | |
| Rodentia | Muridae | Mus | musculus | L. | house mouse | |
| Rodentia | Muridae | Peromyscus | leucopus | (Rafinesque) | white-footed mouse | |
| Rodentia | Muridae | Peromyscus | maniculatus | (Wagner) | American deer mouse | |
| Rodentia | Muridae | Rattus | norvegicus | (Berkenhout) | Norway rat | |
| Rodentia | Muridae | Synaptomys | borealis | Richardson | northern bog lemming | |
| Rodentia | Muridae | Synaptomys | cooperi | Baird | southern bog lemming | |
| Rodentia | Sciuridae | Glaucomys | sabrinus | (Shaw) | northern flying squirrel | |
| Rodentia | Sciuridae | Glaucomys | volans | (L.) | southern flying squirrel | |
| Rodentia | Sciuridae | Marmota | monax | (L.) | woodchuck | |
| Rodentia | Sciuridae | Sciurus | carolinensis | Gmelin | eastern gray squirrel | |
| Rodentia | Sciuridae | Tamias | striatus | (L.) | eastern chipmunk | |
| Rodentia | Sciuridae | Tamiasciurus | hudsonicus | (Erxleben) | red squirrel |
Key to Maine’s orders of mammals
| toes on front foot | toes on hind foot | char. 3 | char. 4 | char. 5 | habitat | |
| Artiodactyla (deer, moose) |
2 or 4 | 2 or 4 | land, water (can swim) | |||
| Carnivora (carnivores) |
0 (seals), 4 (dogs, cats), 5 (remaining carnivores) |
0 (seals), 4 (dogs, cats), 5 (remaining carnivores) |
water, land, trees | |||
| Chiroptera (bats) |
5 | 5 | air (flying) | |||
| Didelphimorphia (opossums) |
5 | 5 | ground, trees | |||
| Eulipotiphya (insectivores) |
ground | |||||
| Lagomorpha (hares, cottontails) |
0 (hair obscures toe pads), 4 (usually visible), 5 |
0 (hair obscures toe pads), 4 (usually visible), 5 |
ground | |||
| Rodentia (rodents) |
4 | 5 | ground, trees, water, air (gliding) |