Juan D. Arias (born May 6, 1938, in Marin, Yaracuy, Venezuela) is a retired Thoroughbred horse trainer best known for race conditioning Canonero II to win the 1971 Kentucky Derby and Preakness Stakes in the United States.^[1] Canonero II would be voted the Eclipse Award as the 1971 American Champion Three-Year-Old Male Horse.^[2]

Arias grew up in poverty on a farm in central Venezuela.^[3] As a child, he had hoped to become a pilot in the Venezuelan air force but suffered a hernia which prevented him from going into the training program. Instead, aged fifteen, he became an apprentice to a local horse trainer, and two years later was accepted into the trainers school at La Rinconada, a race track in Caracas,^[4] and received his training licence on 4 July 1959.^[3]