Carl A. Nafzger (born August 29, 1941, in Plainview, Texas) is an American Hall of Fame horse trainer. Before he was involved in horseracing he was a championship rodeo bull rider. Nafzger trained Unbridled who won the 1990 Kentucky Derby and Breeders' Cup Classic. In 1990 he was voted the Eclipse Award for Outstanding Trainer and the Big Sport of Turfdom Award. In 1994, he wrote a book on the training of Thoroughbred horses titled Traits Of A Winner that was published by R. Meerdink Co. (ISBN 978-0929346328). Nafzger was inducted into the Texas Rodeo Cowboy Hall of Fame in 2008.