William J. "Bill" Passmore Sr. (March 8, 1933 – May 14, 2009) was an American jockey and , who raced thoroughbred horses for 38 years, including at the Kentucky Derby, Preakness Stakes, and Belmont Stakes, winning 3,531 races and $23 million in prize money before spending 20 years as a steward. Passmore died at age 76 in his home in Millersville, Maryland, on May 14, 2009, due to complications from emphysema.