This list shows the IUCN Red List status of the 101 mammal species occurring in Bulgaria. Two of them are endangered, eleven are vulnerable, and four are near threatened. The following tags are used to highlight each species' status as assessed on the respective IUCN Red List published by the International Union for Conservation of Nature:

Order: Rodentia (rodents)

Rodents make up the largest order of mammals, with over 40% of mammalian species. They have two incisors in the upper and lower jaw which grow continually and must be kept short by gnawing. Most rodents are small though the capybara can weigh up to 45 kg (100 lb).

Order: Lagomorpha (lagomorphs)

The lagomorphs comprise two families, Leporidae (hares and rabbits) and Ochotonidae (pikas). Though they can resemble rodents, and were classified as a superfamily in that order until the early 20th century, they have since been considered a separate order. They differ from rodents in having four incisors in the upper jaw rather than two.

Order: Erinaceomorpha (hedgehogs and gymnures)

The order Erinaceomorpha contains a single family, Erinaceidae, which comprise the hedgehogs and gymnures. The hedgehogs are easily recognised by their spines while gymnures look more like large rats.

Order: Soricomorpha (shrews, moles, and solenodons)

The "shrew-forms" are insectivorous mammals. The shrews and solenodons closely resemble mice while the moles are stout-bodied burrowers.

Order: Chiroptera (bats)

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.

Order: Cetacea (whales)

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.

Order: Carnivora (carnivorans)

There are over 260 species of carnivorans, the majority of which eat meat as their primary dietary item. They have a characteristic skull shape and dentition.

Order: Artiodactyla (even-toed ungulates)

The even-toed ungulates are ungulates whose weight is borne about equally by the third and fourth toes, rather than mostly or entirely by the third as in perissodactyls. There are about 220 artiodactyl species, including many that are of great economic importance to humans.

Locally extinct