A miniature horse is a breed or type of horse characterised by its small size. Usually it has been bred to display in miniature the physical characteristics of a full-sized horse, but to be little over 100 cm (40 in) in height, or even less. Although such horses have the appearance of small horses, they are genetically much more similar to pony breeds such as the Shetland. They have various colors and coat patterns.

A pony is a type of small horse. Depending on the context, a pony may be a horse that is under a given height at the withers, or a small horse with a specific conformation and temperament. Compared to a larger horse, a pony may have a thicker coat, mane and tail, with proportionally shorter legs, a wider barrel, heavier bone, a thicker neck and a shorter, broader head. The word pony derives from the old French poulenet, meaning foal, a young, immature horse.