William L. Passmore (March 19, 1910 – November 7, 2002) was a jockey and trainer in both flat and steeplechase Thoroughbred horse racing.
During his career he conditioned horses for prominent owners such as John Sanford, Deborah Rood, Morris Dixon and Bayard Sharp.
In 1952 he trained the colt Hannibal for Sharp with whom he finished eighth in the Kentucky Derby.
His son, William J. Passmore, had a successful career as a jockey and has served as a steward at racetracks in Maryland.
Daughter Patricia Passmore married Eclipse Award winning jockey, Darrel McHargue.