| Named By: | Joseph Leidy in 1858 |
| Time Period: | Early Miocene |
| Location: | Across the USA. Canada, Saskatchewan |
| Size: | About 1 meter tall at the shoulder (withers) |
| Diet: | Herbivore |
| Fossil(s): | Multiple individuals |
| Classification: | | Chordata | Mammalia | Perissodactyla | Equidae | Anchitheriinae | |
| Also known as: | | Hippodon barbouri | Hippodon vellicans | Merychippus socius | Merychippus vellicans | Nannippus niobrarensis | Neohipparion niobrarense | Parahippus barbouri | Parahippus vellicans | Protohippus niobrariensis | |
Parahippus is an extinct relative of the modern horse, very similar to Miohippus, but slightly larger, at around 1 metre (10 hands) tall, at the withers.
Around 20 million years ago, during the Miocene Period, some of Earth's environments were changing, forests and swamps were receding as more plains were developed. It is believed these developments affected many changes in the existing horse ancestors.