Man of Iron, foaled in Kentucky in 2006, is an American Thoroughbred racehorse. Sired by Giant's Causeway and out of the mare Better Than Honour, he was bred by Skara Glen Stables. He was sold as a yearling to Racing Partners Smith/Magnier/Tabor, who turned over his training to Aidan O'Brien. On November 6, 2009, he won the most important race of his career: the Breeders' Cup Marathon. In the 14-furlong race, he fought off Cloudy's Knight to win by a nose.