A pony is a breed of horse which has a number of distinct traits, most notably a small size. Numerous pony breeds can be found all over the world, and some well known representatives of this equine group include Shetland, Welsh, and Connemara ponies. Just like their larger relatives, ponies have been used for work, sport, and pleasure for thousands of years, and they are incredibly diverse creatures.

A pony is not merely a small horse. There are several distinct physical differences between horses and ponies which make the two easy to distinguish. Ponies tend to very stocky, with thick bones, wide chests, and small heads. Their manes, tails, and coats are often thicker than those of horses, perhaps because many pony breeds evolved in colder climates where a thick layer of insulation would be vital.

Ponies are also incredibly strong for their size, thanks to their muscular bodies. A mature pony can sometimes pull the same weight as a draft horse, for example, and many ponies are capable of carrying adult riders. Pound for pound, ponies are much stronger than horses. They are also known for being extremely hardy, and tolerant of a wide range of conditions including extreme cold. The pony is also famous for being extremely intelligent, and sometimes a bit stubborn.

The official definition of a pony is a horse under 14.2 hands. The hand system of measurement used for horses can be a bit confusing. The height of a horse is measured to its withers, the high part of a horse's shoulders. A “hand” is four inches or 10.16 centimeters, with each number after the decimal point representing an additional inch, so a pony can be up to almost five feet tall (or 147 centimeters). However, the 14.2 hand standard is not hard and fast. Some pony breeds occasionally produce individuals which are taller, while some horses measure in at below 14.2 hands, but they are still classified as horses because of the breeds to which they belong.

Some people think of ponies primary as children's horses, but ponies have been used as work animals and to carry adults for thousands of years. Many children get their start as riders on ponies because a well trained pony is easier to handle than an adult horse for a younger rider. Just like horses, ponies are shown in a variety of classes, and they can also be found working on farms, carrying people in the hunt field, and drawing carts and carriages for both leisure and transportation.