Spanish Mustangs are sometimes confused with the American Mustang, feral horses descended from both Spanish horses and other feral horses escaped from various sources that currently run wild in protected areas of the American west, currently managed by the Bureau of Land Management (BLM). However, the true Spanish Mustang differs from the "wild" American Mustang in appearance and ancestry.

Spanish Mustangs, also called Colonial Spanish Horses, are of great historic importance. They descend from horses introduced from Spain during the age of the conquest of the Americas. They are a type that is mostly or wholly extinct now in Spain.