Gun Runner (foaled March 8, 2013) is a retired American Thoroughbred racehorse who was the 2017 American Horse of the Year after winning four Grade I races at age four. He retired with earnings of nearly $16 million. As a three-year-old, he became one of the early favorites for the 2016 Kentucky Derby after winning both the Risen Star Stakes and Louisiana Derby. Following a third-place finish in the Kentucky Derby, he won the Matt Winn Stakes and Clark Handicap, and was second in the Breeders' Cup Dirt Mile and Pennsylvania Derby.