The 2003 King George VI and Queen Elizabeth Stakes was a horse race held at Ascot Racecourse on Saturday 26 July 2003. It was the 53rd King George VI and Queen Elizabeth Stakes. The winner was Aga Khan's Alamshar, a three-year-old bay colt trained in Ireland by John Oxx and ridden by Johnny Murtagh. Alamshar's victory was the first in the race for his jockey and trainer and the second for the Aga Khan after Shergar (1981).