Equipoise (1928–1938) was an American Thoroughbred racehorse and sire. In a career which lasted from 1930 until 1935, he ran fifty-one times and won twenty-nine races. A leading two-year-old in 1930, he missed most of the next season, including two of the three American Triple Crown races through injury and illness. "Ekky" returned to the track in 1934 and proved to be a dominant champion, winning numerous important stakes races in the next three years. Equipoise died in 1938 after a short but promising stud career.
Equipoise was a chestnut bred in the United States by Harry Payne Whitney and owned by his son, Cornelius Vanderbilt Whitney. He was called the "Chocolate Soldier" by his fans, due to his elegance and symmetry. His sire, Pennant, won the Belmont Futurity Stakes for Harry Payne Whitney in 1913. Equipoise's dam, Swinging, was a descendant of the Epsom Oaks winner Miami, placing him in the same Thoroughbred family as the 1897 English Triple Crown winner Galtee More and the 1902 Epsom Derby winner Ard Patrick as well as some well-known American runners, such as Intentionally and Seabiscuit.
As a yearling, Equipoise was an unimpressive individual. C. V. Whitney thought so little of the ugly duckling that he sent him to his second-string trainer, Fred Hopkins.
As a two-year-old, Equipoise ran sixteen times, claiming his first stakes victory when he won the Keene Memorial Stakes at Belmont Park. In September, he ran in the Belmont Futurity the most valuable two-year-old race of the season in which he was beaten a nose by Jamestown. Although Jamestown's victory was regarded by some as having decided the identity of the best two-year-old, he did not race again in 1930, while Equipoise went on to further success. On November 5, he beat Twenty Grand by half a length with Mate a neck away in third in the Pimlico Futurity. After starting slowly, he settled the race in the straight with what the New York Times described as "a brilliant burst of speed" to reverse two earlier defeats by Twenty Grand. When his jockey, Sonny Workman, was asked if this was his greatest race, Workman replied: "My greatest race? Hell, it may have been the greatest race anybody ever saw."