[4] Moon Madness began his three-year-old season by winning minor handicap races including victories at Newmarket and Haydock.
[5] He recorded his first important success when winning the King George V Stakes, a handicap race for three-year-olds at Royal Ascot in "impressive" style.
In August he was sent to York to contest the Great Voltigeur Stakes, an important trial race for the St Leger in which he finished third behind Nisnas and Mashkour.
Ridden by Pat Eddery, Moon Madness drew away from his opponents in the straight to win "comfortably" by four lengths from Celestial Storm and Untold.
He returned to England to contest the King George VI and Queen Elizabeth Stakes, but finished unplaced behind Reference Point.
[9] In August, Moon Madness won the Geoffrey Freer Stakes, beating a field which included Legal Bid and Ibn Bey (runner-up in the Breeders' Cup Classic).