The following list of horse and pony breeds includes standardized breeds, some strains within breeds that are considered distinct populations, types of horses with common characteristics that are not necessarily standardized breeds but are sometimes described as such, and terms that describe groupings of several breeds with similar characteristics.
While there is no single definition of the term "breed", it can be defined as a population sharing common ancestry, which has been subjected to similar selection objectives, and which conforms to certain established “breed standards”. Its members may be called purebred. In most cases, bloodlines of horse breeds are recorded with a breed registry. The concept is somewhat flexible in horses, as open stud books are created for recording pedigrees of horse breeds that are not yet fully true-breeding.