Croydon Airport (EGCR) was an airport in South London which straddled the boundary between what are now the London boroughs of Croydon and Sutton. Croydon was the first airport in the world to introduce air traffic control, in 1921. It was the main airport for London before it was replaced by Northolt Aerodrome, London Heathrow Airport and London Gatwick Airport.

It originated as two adjacent World War I airfields - Beddington Aerodrome, one of a number of small airfields around London, which had been created for protection against the Zeppelin raids in about May 1915, and Waddon Aerodrome of 1918, a test-flight aerodrome adjoining National Aircraft Factory No 1. Croydon Airport's Aerodrome Hotel is part of Croydon Vision 2020 regeneration plan.

At the end of World War I, the two airfields were combined into  London's official airport as the gateway for all international flights  to and from the capital. Croydon Aerodrome opened on 29 March 1920.

It stimulated a growth in regular scheduled flights carrying passengers, mail and freight, the first destinations being Paris, Amsterdam and Rotterdam. In 1923 Berlin flights were added. It was the operating base for Imperial Airways, remembered in the road name Imperial Way on the site today.

In the mid 1920s the airfield was extended, some adjacent roads such  as Plough Lane being closed to allow heavier airliners to land and  depart safely. A new complex of buildings was constructed adjoining Purley Way, including the first purpose-designed air terminal in the world, the Aerodrome Hotel and extensive hangars, at a cost of £267,000 (£11.5 million in today's prices). Although the first day of operation using the new building and layout  was 30 January, the official opening was not until 2 May 1928.