Horse family in the order Perissodactyla, which includes the odd-toed hoofed animals. Besides the domestic horse, wild asses, wild horses, onagers, and zebras, there are numerous extinct species known from fossils.

All species in the family are inhabitants of flat, open country, except the mountain zebra from the hills of southern Africa. They have long legs, adapted to carry the animals at speed over firm ground; only one toe, terminating in a hoof, is present on each limb. They are all herbivorous and have keen senses to detect their enemies. Their jaws are strong and able to chew the tough grasses and herbs on which they feed in the wild state.