John Shirreffs, an American racehorse trainer best known for conditioning Hall of Fame mare Zenyatta and 2005 Kentucky Derby winner Giacomo, died February 12, 2026. He was 80. His cause of death was undisclosed.
Owner Lee Searing said Shirreffs died in his sleep overnight Wednesday into Thursday morning and was found on the couch by his wife, Dottie Ingordo-Shirreffs. At the time of his death, Searing said there were 12 horses in the Shirreffs barn, including Grade I winner Baeza and Westwood.
Shirreffs’ biggest headline came when he won the 2005 Kentucky Derby with Giacomo, a 50-1 longshot. He later built one of modern racing’s defining campaigns with Zenyatta, guiding her through a 19-race win streak and 13 Grade 1 victories.
In 2009, Shirreffs saddled Zenyatta to the Breeders’ Cup Classic, making her the only female winner of that race. The same year, he also trained Ladies’ Classic winner Life Is Sweet, a rare feat that put his program at the center of the sport’s biggest weekend.
Based in Arcadia, California, Shirreffs was widely associated with a steady, kindness-first style that helped top horses stay calm enough to perform on the biggest stages. His final graded-stakes win came when Westwood captured the GII San Pasqual S. at Santa Anita on January 31, closing a career defined by elite results and a fan-forward approach to presenting his stars.