Noble Threewitt (February 24, 1911 – September 17, 2010) was an American Thoroughbred racehorse trainer who conditioned horses for seventy-five years before retiring on his ninety-sixth birthday. The city of Arcadia, California, home to Santa Anita Racetrack, declared February 24, 2007 to be "Noble Threewitt Day." A long-time friend of trainer Charlie Whittingham, in 1993 Hollywood Park Racetrack named its new Horsemen's Lounge in their honor.