Reindeer, a deer that inhabits the far northern regions of Europe and Asia and is almost indispensable to the life of many Arctic peoples. The reindeer has been partially domesticated for centuries, and it is doubtful if there are any purely wild strains left in the Old World. The North American caribou is a larger, untamed reindeer.

The reindeer is about 6 feet (1.8 m) long and stands 3 feet (1 m) high at the shoulder. It is one of the few deer in which both male and female have antlers. The antlers are flat, branching, and widespread. They bend back over the neck and forward again. The reindeer's coat is thick and ranges in color from white to brown. The reindeer has relatively large hooves, giving it good footing on snow and ice. A long dewlap (fold of skin) hangs from its neck.

Reindeer feed on lichens and mosses. They migrate in large herds in search of food, and the peoples who depend upon them follow the migrations.

Until well into the 20th century Laplanders of northern Europe extensively used reindeer for transportation because the animal is swift and can pull heavy loads for long distances. The reindeer is still used for meat and milk, and its hide is used for clothing and shelter. The hollow and buoyant hair is used to stuff life preservers. The strong sinews are used as thread and twine, and the antlers are carved into knife handles and other useful or ornamental objects.

Between 1891 and 1902 the United States government imported 1,300 reindeer from Siberia into Alaska to serve as food for Eskimo tribes. The animals increased to one million in 30 years, but commercial hunting by white hunters reduced the herds to 10,000. In 1972 state wildlife officials imposed quotas to protect some of the herds. In the 1930's the Canadian government brought a herd of reindeer into the Yukon for the use of the Eskimos of that region.

The reindeer is Rangifer tarandus of the family Cervidae.