Archaeotherium (Greek: αρχαιοθήριον, meaning "ancient beast") is an extinct genus of entelodont artiodactyl endemic to North America and Eurasia during the Eocene and Oligocene epochs (33.9—24.8 mya), existing for approximately 9.1 million years.[1] Archaeotherium was about 1.2 m (3 ft 11 in) tall at the shoulder and around 2 m (6 ft 7 in) long and weighing around 270 kg (600 lb).

Although superficially pig-like, Archaeotherium, along with all other entelodonts, was more closely related to anthracotheres, hippopotamuses, and whales. Evidence from the Wyoming Dinosaur Center suggests that the omnivorous Archaeotherium, like many modern predatory mammals, kept caches of food for times when their hunting was less successful.

Community content is available under CC-BY-SA unless otherwise noted.