Rayon d'Or (1876–1896) was a French Thoroughbred racehorse and Champion sire in the United States. Bred by at his stud farm in Dangu, Eure, he was sired by whose wins included the Prix Morny (1872), Goodwood Cup (1873) and Jockey Club Cup (1873) and whom Rayon d'Or would help make the Leading sire in Great Britain and Ireland in 1879. Rayon d'Or's dam was the good producing mare Araucaria, sired by Ambrose. Araucaria was the last foal of the mare Pocahontas whom Thoroughbred Heritage says is "one of the most influential thoroughbreds of all time, male or female."