Diamond Jubilee was a British-bred and British-trained Thoroughbred race horse and sire. In a career which lasted from June 1899 until October 1901 he ran sixteen times and won six races.

The Triple Crown of Thoroughbred Racing, often shortened to Triple Crown, is a series of horse races for Thoroughbreds, often restricted to three-year-olds. Winning all three of these Thoroughbred horse races is considered the greatest accomplishment in Thoroughbred racing. The term originated in mid-19th-century England and nations where Thoroughbred racing is popular each have their own Triple Crown series.