Graustark (1963–1988) was an American Thoroughbred racehorse who was a favorite to win the 1966 Kentucky Derby until an injury prematurely ended his career.
Bred by renowned sportsman John W. Galbreath at his Darby Dan Farm near Lexington, Kentucky, Graustark was named for the fictional country used as the setting in several early 20th century novels by George Barr McCutcheon.
Sired by European champion Ribot, Graustark was born in the same year as Ogden Phipps' future Hall of Fame colt Buckpasser.
Racing on a very muddy track, he was in front by six lengths in the back stretch but lost by a nose to Abe's Hope (who nearly beat Buckpasser in the Flamingo Stakes).
Among his progeny were Proud Truth, Prove Out, Key To The Mint, Avatar, Caracolero, Protection Racket, Gregorian and Jim French.