Common Ringtails are the smallest of eight species of ringtail possums that live in Australia. The adults of this species typically are between 30 and 35 cm in body length, with a tail length that is roughly equal to the body length. They have brown or reddish fur on the upper surfaces of the body and light colored or gray fur on the ventral surfaces, with large eyes which are well adapted to seeing at night. Two of the claws found on the front feet are opposable and the pads, as well as the tips, of the toes are grooved. They possess a strong, but relatively hairless, prehensile tail. This tail is carried tightly curled when not in use. These animals can be distinguished from other possum species in several ways. Their ears are smaller and more rounded and they typically have patches of white fur both on and above the ears. The tail of Common Ringtail has a white tip and is tapered.

Common Ringtails have an extensive distribution. They occur in temperate or tropical areas but are rarely found in drier areas. It is thought that this wide habitat range is due to their ability to feed on a number of different plant species. They can usually be found in dense brush forests, as they favor environments that are plentiful with eucalyptus. Nests are mostly found in hollow trees lined with leaves. P. peregrinus constructs a large spherical drey of shredded bark, twigs and leaves in dense shrubbery.

Common Ringtails are nocturnal and primarily folivorous. They feed mainly on eucalyptus leaves, but may also eat flowers, buds, nectar, and fruit. A low metabolic rate helps to compensate for the low energy intake of these mammals due to their specialized diet. Common ringtail possums prefer eating the youngest foliage of the plants they consume. This effects reproductive patterns, as the young leave the pouch and are weaned during times when flower and fruit growth peaks.

Breeding occurs from April - November with a litter of 2 young. The female's pouch has a forward facing opening; two of the four nipples are functional at one time. Older females can produce up to two litters of young per year. Initial growth of their young is generally slow.

They habitat Australia: Cape York Peninsula (Queensland) to SE South Australia and SW Western Australia, Tasmania, and islands of the Bass Straits.