Merychyus is an extinct genus of oreodont of the family Merycoidodontidae, endemic to North America. It lived during the Miocene, 20.4—10.3 mya, existing for approximately 10 million years. Fossils are widespread through the central and western United States. Merychyus was a herbivore with a short face, tusk-like canine teeth, heavy body, long tail, short feet, and four-toed hooves.