This list of mammals of Colorado lists every wild mammal species seen in the U.S. state of Colorado, based on the list published by the Colorado Division of Wildlife.
- Bobcat, Lynx rufus
- Canada lynx, Lynx canadensis
- Cougar, Puma concolor
- Ringtail, Bassariscus astutus
- Raccoon, Procyon lotor
- Pronghorn, Antilocapra americana
- Elk, Cervus canadensi
- Moose, Alces alces
- Mule deer, Odocoileus hemionus
- White-tailed deer, Odocoileus virginianus
- Mountain goat, Oreamnos americanus
- Bighorn sheep, Ovis canadensis
- Kit fox, Vulpes macrotis
- Swift fox, Vulpes velox
- Red fox, Vulpes vulpes
- Gray fox, Urocyon cinereoargenteus
- Coyote, Canis latrans
- Gray wolf, Canis lupus EX
- American black bear, Ursus americanus
- Grizzly bear, Ursus arctos EX
- Western spotted skunk, Spilogale gracilis
- Eastern spotted skunk, Spilogale putorius
- Striped skunk, Mephitis mephitis
- American hog-nosed skunk, Conepatus leuconotus
- Ermine, Mustela erminea
- Long-tailed weasel, Mustela frenata
- Black-footed ferret, Mustela nigripes EN
- American mink, Mustela vison
- American marten, Martes americana
- American badger, Taxidea taxus
- North American river otter, Lontra canadensis
- Wolverine, Gulo gulo EN
- Virginia opossum, Didelphis virginiana
- Nine-banded armadillo, Dasypus novemcinctus
- North American beaver, Castor canadensis
- Plains pocket gopher, Geomys bursarius
- Yellow-faced pocket gopher, Pappogeomys castanops
- Botta’s pocket gopher, Thomomys bottae
- Northern pocket gopher, Thomomys talpoides
- Ord’s kangaroo rat, Dipodomys ordii
- Hispid pocket mouse, Chaetodipus hispidus
- Olive-backed pocket mouse, Perognathus fasciatus
- Plains pocket mouse, Perognathus flavescens
- Silky pocket mouse, Perognathus flavus
- Great Basin pocket mouse, Perognathus merriami
- Meadow jumping mouse, Zapus hudsonius
- Western jumping mouse, Zapus princeps
- North American porcupine, Erethizon dorsatum
- Sagebrush vole, Lemmiscus curtatus
- Long-tailed vole, Microtus longicaudus
- Mexican vole, Microtus mexicanus
- Montane vole, Microtus montanus
- Prairie vole, Microtus ochrogaster
- Meadow vole, Microtus pennsylvanicus
- Southern red-backed vole, Myodes gapperii
- Muskrat, Ondatra zibethicus
- Western heather vole, Phenacomys intermedius
- White-throated woodrat, Neotoma albigula
- Bushy-tailed woodrat, Neotoma cinerea
- Eastern woodrat, Neotoma floridana
- Desert woodrat, Neotoma lepida
- Mexican woodrat, Neotoma mexicana
- Southern plains woodrat, Neotoma micropus
- Brush mouse, Peromyscus boylii
- Canyon mouse, Peromyscus crinitus
- White-footed mouse, Peromyscus leucopus
- Deer mouse, Peromyscus maniculatus
- Northern rock mouse, Peromyscus nasutus
- Pinyon mouse, Peromyscus truei
- Western harvest mouse, Reithrodontomys megalotis
- Plains harvest mouse, Reithrodontomys montanus
- Northern grasshopper mouse, Onychomys leucogaster
- Hispid cotton rat, Sigmodon hispidus
- Abert’s squirrel, Sciurus aberti
- Fox squirrel, Sciurus niger
- American red squirrel, Tamiasciurus hudsonicus
- White-tailed antelope squirrel, Ammospermophilus leucurus
- Gunnison’s prairie dog, Cynomys gunnisoni
- White-tailed prairie dog, Cynomys leucurus
- Black-tailed prairie dog, Cynomys ludovicianus
- Northern flying squirrel, Glaucomys sabrinus
- Yellow-bellied marmot, Marmota flaviventris
- Wyoming ground squirrel, Spermophilus elegans
- Golden-mantled ground squirrel, Spermophilus lateralis
- Spotted ground squirrel, Spermophilus spilosoma
- Thirteen-lined ground squirrel, Spermophilus tridecemlineatus
- Rock squirrel, Spermophilus variegatus
- Cliff chipmunk, Tamias dorsalis
- Least chipmunk, Tamias minimus
- Colorado chipmunk, Tamias quadrivittatus
- Hopi chipmunk, Tamias rufus
- Uinta chipmunk, Tamias umbrinus
- American pika, Ochotona princeps
- Desert cottontail, Sylvilagus audubonii
- Eastern cottontail, Sylvilagus floridanus
- Mountain cottontail, Sylvilagus nuttallii
- Pygmy rabbit, Brachylagus idahodensis
- Snowshoe hare, Lepus americanus
- Black-tailed jackrabbit, Lepus californicus
- White-tailed jackrabbit, Lepus townsendii
- Elliot’s short-tailed shrew, Blarina hylophaga
- North American least shrew, Cryptotis parva
- Crawford’s gray shrew, Notiosorex crawfordi
- Cinereus shrew, Sorex cinereus
- American pygmy shrew, Sorex hoyi
- Merriam’s shrew, Sorex merriami
- Montane shrew, Sorex monticolus
- Dwarf shrew, Sorex nanus
- American water shrew, Sorex palustris
- Eastern mole, Scalopus aquaticus
- Silver-haired bat, Lasionycteris noctivagans
- California myotis, Myotis californicus
- Western small-footed myotis, Myotis ciliolabrum
- Long-eared myotis, Myotis evotis
- Little brown bat, Myotis lucifugus
- Fringed myotis, Myotis thysanodes
- Long-legged myotis, Myotis volans
- Yuma myotis, Myotis yumanensis
- Pallid bat, Antrozous pallidus
- Big brown bat, Eptesicus fuscus
- Spotted bat, Euderma maculatum
- Eastern red bat, Lasiurus borealis
- Hoary bat, Lasiurus cinereus
- Western pipistrelle, Parastrellus hesperus
- Townsend’s big-eared bat, Corynorhinus townsendii
- Big free-tailed bat, Nyctinomops macrotis
- Mexican free-tailed bat, Tadarida brasiliensis