The King George VI and Queen Elizabeth Stakes is a Group 1 flat horse race in Great Britain which is open to thoroughbreds aged three years or older. It is run at Ascot over a distance of 1 mile and 4 furlongs (2,414 metres), and it is scheduled to take place each year in late July.

It is Britain's most prestigious open-age flat race, and its roll of honour features some of the most highly-acclaimed horses of the sport's recent history. The 1975 running, which involved a hard-fought battle to the finish between Grundy and Bustino, is frequently described as the "race of the century" . Many of its winners subsequently compete in the Prix de l'Arc de Triomphe, and a number go on to have a successful career at stud. The race is often informally referred to as the "King George".

The event was formed as the result of an amalgamation of two separate races at Ascot which were established in 1946 and 1948 . The first of these, named after King George VI, was a 2-mile contest for three-year-olds held in October. The second, in honour of his consort Queen Elizabeth, was a 1½-mile event staged in July. The idea was conceived by Major Crocker Buteel, the Clerk of the Course at Ascot, who wanted to create an important international race over 1½ miles for horses aged three or older. The inaugural running of the combined race took place on July 21, 1951. In its first year, to commemorate the Festival of Britain, it was titled the "King George VI and Queen Elizabeth Festival of Britain Stakes".