Bighorn, or Bighorn Sheep, a wild sheep of western North America. It is also called mountain sheep and Rocky Mountain bighorn sheep.

The bighorn is dark brown or tan with a white belly, rump, and muzzle. It has small ears and a short tail. It is about three feet (90 cm) high at the shoulder and weighs up to 300 pounds (136 kg). The male, or ram, has massive brown horns that form spirals along the sides of the head. The female, or ewe, has small, spike-shaped horns. During the mating season, rams compete for dominance by crashing their horns together.

Bighorn feed on grasses, woody plants, and berries. During the winter, they migrate from high mountain slopes to valleys in search of food. Bighorn are game animals and are highly prized for their meat, and their horns are valued as trophies.

The bighorn is Ovis canadensis of the family Bovidae.