W. Bret Calhoun (born May 12, 1964, in Dallas, Texas) is an American Thoroughbred racehorse trainer.
The son of a school teacher who also owned and trained horses, he attended Texas Tech University but left before graduating.
Calhoun began his professional training career in 1993 and earned his first win on April 1, 1994.
In Kentucky in 2008, Calhoun won the Aegon Turf Sprint Stakes at Churchill Downs and the Grade I Shakertown Stakes at Keeneland Race Course with Mr. Nightlinger.
In 2008, Bret Calhoun finished fourth in total wins for the year among all trainers in the United States.