A native of Great Britain, Simon Callaghan set up his stable in Southern California in 2009. His father Neville is a top trainer at Newmarket, and Callaghan grew up assisting with various training and horse care duties.
Callaghan has established himself as a top up-and-coming trainer, having trained multiple Grade 1 winners in less than 5 years in the United States. Top horses include Dubawi Heights, Byrama, Belle Royale and Slim Shadey. He trains 2014 Santa Anita Oaks winner and leading Kentucky Oaks contender Fashion Plate.