This is a list of the mammal species recorded in the Cook Islands. There are seven mammal species in the Cook Islands, of which one is labelled as being a vulnerable species.[1]
The following tags are used to highlight each species' conservation status as assessed by the International Union for Conservation of Nature:
| EX | Extinct | No reasonable doubt that the last individual has died. | |
| EW | Extinct in the wild | Known only to survive in captivity or as a naturalized populations well outside its previous range. | |
| CR | Critically endangered | The species is in imminent risk of extinction in the wild. | |
| EN | Endangered | The species is facing an extremely high risk of extinction in the wild. | |
| VU | Vulnerable | The species is facing a high risk of extinction in the wild. | |
| NT | Near threatened | The species does not meet any of the criteria that would categorise it as risking extinction but it is likely to do so in the future. | |
| LC | Least concern | There are no current identifiable risks to the species. | |
| DD | Data deficient | There is inadequate information to make an assessment of the risks to this species. |
The bats' most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals capable of flight. Bat species account for about 20% of all mammals.
The order Cetacea includes whales, dolphins and porpoises. They are the mammals most fully adapted to aquatic life with a spindle-shaped nearly hairless body, protected by a thick layer of blubber, and forelimbs and tail modified to provide propulsion underwater.
There are over 260 species of carnivorans, the majority of which feed primarily on meat. They have a characteristic skull shape and dentition.