Taghrooda has been retired after a brilliant year in which she won the Oaks and the King George VI and Queen Elizabeth Diamond Stakes.
Owner Sheikh Hamdan Al Maktoum has retired the horse after she finished third in the Prix de l'Arc de Triomphe.
He also retired Coral-Eclipse winner Mukhadram, trained by William Haggas.
Mukahadram was third in the King George to Taghrooda, who was described by the sheikh's racing manager Angus Gold as an "an absolute star".
A daughter of 2009 Derby and Arc winner Sea The Stars, Taghrooda won four of her six starts and will begin a breeding career next year.
The decision means both Classic winners from Epsom in June will not race again, after Derby victor Australia was retired on Saturday.