The Grosvenor Challenge Cup, commonly known as the Grosvenor Cup, was a trophy presented by Lord Edward Grosvenor in 1923 to the winner of a light aircraft time trial competition. Entries were initially restricted to British designs using aero engines of less than 150 horsepower. The first competitions were held at Lympne Aerodrome in Kent. The contest continued until 1935 with a break to 1949 when the Royal Aero Club resumed the races at Elmdon where the entry was opened to British and international designs with a weight less than 1,000 kilograms.