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.

Merychyus was a herbivore with a short face, tusk-like canine teeth, heavy body, long tail, short feet, and four-toed hooves.

[2] Merychyus was a common prey item for the beardog Daphoenodon, as over half of all herbivore remains uncovered from Daphoenodon burrows at Agate Fossil Beds belonged to Merychyus.

Nebraska and Wyoming; A paleobiota entombed in fine-grained volcaniclastic rocks.