The Cotillion Stakes is an American Thoroughbred horse race held annually at Parx Racing and Casino in Bensalem, Pennsylvania. Since 2010, it has been raced on the first Saturday in October as a prelude to the annual Breeders' Cup World Thoroughbred Championships. Prior to this change in date, it was held in September or October, usually a week or two before the Breeders' Cup; the new date annually attempts to draw a stronger field. The race is open to three-year-old filles, willing to race one and one-sixteenth miles (eight and a half furlongs) on the dirt. The Grade I event carries a purse of $1,000,000.
This race, which was inaugurated in 1969 at Liberty Bell Park in Northeast Philadelphia before thoroughbred racing moved to the then-Keystone Park (later known as Philadelphia Park) in nearby Bensalem in Bucks County, Pennsylvania, has produced five Eclipse Award winners. One of them is the multiple winner Susan's Girl who won this race in 1972. Starting in 2009, a "Ladies Day at the Races" is held, featuring several races featuring female jockeys.