The British Champions Sprint Stakes is a Group 1 flat horse race in Great Britain open to horses aged three years or older.
It is run at Ascot over a distance of 6 furlongs (1,207 metres), and it is scheduled to take place each year in October.
It was named after Diadem (foaled 1914), a winner of several of Ascot's leading races.
The current system of race grading was introduced in 1971, and the Diadem Stakes initially held Group 3 status.
It became part of the newly created British Champions Day, and its purse was increased to £250,000.