Wild sheep are found in North America, Asia, northern Africa, and certain parts of Europe. They are of no commercial importance although in Africa and Asia they are sometimes killed for their meat and hides. There are eight species. Wild sheep range in body length from about 4 feet (1.2 m) to more than 6 feet (1.8 m), not including a 3- to 10-inch (7.5- to 25-cm) tail. Weight is from about 110 to 440 pounds (50-200 kg), depending on the species, individual, and sex. Wild sheep, like domestic sheep, live in flocks. Often it is difficult to tell wild sheep from wild goats; the two are closely related.

The aoudad, or Barbary sheep, lives in rough, barren, rocky areas of northern Africa. It has a reddish-tan color and a unique feature—a mane of long, soft hairs on the throat, chest, and upper parts of the forelegs. The horns, found on both male and female, are heavy and ridged and curve outward, backward, and then inward.

The bharal, also called burrhel, or blue sheep, is found in central Asia at elevations of about 12,000 to 16,000 feet (3,700-4,900 m). This species is distinguished by the shape of its horns, which are rounded and smooth, and curve backward and outward. They are borne by both sexes. The animal is blue-gray on the upper body and on the outside of the legs. The underparts and inside of the legs are white.

The other six species of wild sheep are all of the same genus and are sometimes referred to collectively as true sheep. This genus includes the bighorn sheep, Dall sheep, argali, urial (also called red sheep and Asiatic mouflon), Laristan sheep, and mouflon. In these species, color varies from whitish to gray or brown. Some have lighter markings. The males have massive spiral horns; the females have short horns that are only slightly curved. These sheep are found in fairly dry upland and mountainous areas. (It is from members of this genus that most zoologists believe the domestic sheep developed.)

Two species are found in North America—the bighorn sheep and the Dall sheep. The Dall sheep is found in Alaska and northwestern Canada. It is usually white all over, although gray individuals are found occasionally.

The domestic sheep and true sheep belong to the genus Ovis. The domestic sheep is O. aries; the Dall sheep, O. dallii. The bharal is Pseudois nayaur, the aoudad, Ammotragus lervia. All are of the family Bovidae.