English-born American jockey who, in a career of 40 years (1927–66), established a world record in Thoroughbred racing with 6,032 victories (some sources give 6,026). This mark was surpassed in 1970 by Willie Shoemaker (Shoemaker, Bill). On May 15, 1952, Longden became the first jockey in the United States to ride 4,000 winners and the second in the world to do so. (Two years earlier, Gordon Richards (Richards, Sir Gordon) of England had achieved that feat.) On February 28, 1957, Longden became the first to ride 5,000 winners.

Longden emigrated with his family from England to Canada in 1912, and he began his racing career in Utah in 1927. In 1943 he rode Count Fleet to victory in the Triple Crown events of U.S. Thoroughbred racing (the Kentucky Derby, the Preakness Stakes, and the Belmont Stakes). For three seasons (1938 and 1947–48) he led American jockeys in races won. After his retirement from riding, he became a Thoroughbred trainer and breeder. One of his horses, Majestic Prince, won the Kentucky Derby in 1969.