Cat Thief is an American Thoroughbred racehorse. He is the son of Storm Cat, an outstanding Champion sire and the grandson of both the 20th Century's most important sire, Northern Dancer and whose damsire was the U.S. Triple Crown champion, Secretariat. Cat Thief's dam was the multiple stakes winner, Train Robbery, a daughter of U.S. Racing Hall of Fame inductee Alydar.