What is the fastest horse in history?

Secretariat, an American Thoroughbred racehorse, in 1973, was to become the first Triple Crown winner in 25 years. Secretariat was an American Thoroughbred racehorse who, in 1973, became the first Triple Crown winner in 25 years. The fastest horse on dirt from 1 3/16 to 1 5/8 miles in history. Although Quarter Horses, American breed of horse that excels at sprinting short distances, attains higher speeds over shorter distances than Thoroughbreds.