Uintaceras is an extinct genus of medium-sized early rhinocerotoids that lived in North America (Wyoming and Utah) during the Middle Eocene, with only the type species U. radinskyi, named in 1997, currently contained within the genus.

[1][2] Traditionally considered the oldest and most primitive species of the Rhinocerotidae, it may instead have been a close relative of the Asian Paraceratheriidae.

[3] The dubious species Forstercooperia (Hyrachyus) grandis (Radinsky, 1967; Peterson, 1919)[4][5] is also possibly the same animal as Uintaceras,[2][6] although the Asian material of F. grandis was assignable to Forstercooperia confluens.

Uintaceras weighed about 220 kilograms (490 lb) when fully grown.

[citation needed] It was a relatively slender animal and Uintaceras resembled a typical hyracodontid (e.g. Hyracodon), but differed from the hyracodonts due to the presence of a primitive four-fingered hand and a number of other features of the structure of the legs, which were clearly not intended for fast and long running.