King T. Leatherbury (born March 26, 1933, in Shady Side, Maryland) is an American Thoroughbred racehorse trainer who ranks fifth all-time in wins among U.S. trainers.^[1]

Called a Maryland racing legend^[2] by Churchill Downs, King T. Leatherbury, along with John J. Tammaro, Jr., Richard E. Dutrow, Sr. and Hall of Fame inductee Bud Delp, were known as Maryland racing's "Big Four". They dominated racing in Maryland during the 1960s and 1970s and helped modernize flat racing training.

Born on a farm there, where his father raised horses, King Leatherbury graduated from the University of Maryland with a degree in business administration then chose a career in thoroughbred racing. As a trainer, he won his first race in 1959 at Florida's Sunshine Park but made his reputation at racetracks in his native Maryland. He was the leading trainer at Delaware Park Racetrack on four occasions, won twenty titles at Laurel Park Racecourse and another twenty-five at Pimlico Race Course. He led all Maryland trainers in wins for four straight years between 1993 through 1996 and has won five races in one day four times and on another occasion won six races on one card.

On April 20, 2015, Leatherbury's induction into the National Museum of Racing and Hall of Fame was announced. His formal induction took place in ceremonies on August 7, 2015, in Saratoga Springs, NY.^[3]