Katherine "Kathy" Ritvo (born February 13, 1969) is a race horse trainer who won the Breeders' Cup Classic in 2013 with Mucho Macho Man after having finished a close second in the same race in 2012. She is the first woman to have trained a winner of that race. She also was only the fifth woman trainer to win any Breeders' Cup race, and was the 14th woman trainer to saddle a starter in the Kentucky Derby in the 137 years that race had been run by 2011.