Eight Thirty (March 27, 1936 – April 7, 1965) was an American Hall of Fame Thoroughbred racehorse. He was owned by George D. Widener Jr. and bred by his Erdenheim Farm. Widener is one of only five people ever named an Exemplar of Racing. Eight Thirty was a descendant of Fair Play, who had been purchased from the estate of August Belmont Jr. by Widener's uncle, Joseph E. Widener.

Racing at age two in 1938, Eight Thirty won two important graded stakes races but was overshadowed by William Ziegler Jr.'s Champion 2-Yr-Old Colt El Chico.

In 1939, Eight Thirty started his three-year-old racing season slowly and did not enter any of the American Classic Races. However, competing in the East Coast racing scene along with greats such as Johnstown and Challedon, in one month alone, Eight Thirty won four straight important stakes races. He ended his season with seven wins out of his ten starts. Racing at age four and five, he won six of ten starts while setting a track record in his win in the 1940 Massachusetts Handicap.

Retired to stud duty at his owner's breeding farm, Eight Thirty proved to be a successful Stallion. He sired 44 stakes winners and was the damsire of 1962 Belmont Stakes winner Jaipur. Eight Thirty died on April 7, 1965.

Eight Thirty was inducted into the National Museum of Racing and Hall of Fame in 1994.

• Eight Thirty's pedigree and racing stats
• Fair Play at the United States' National Museum of Racing and Hall of Fame Archived 2006-12-30 at the Wayback Machine