Roundshaw is a housing estate and park in south Wallington on the eastern edge of the London Borough of Sutton. Grid Ref TQ302633. It was built on part of the site of the former Croydon Airport, and occupying roughly the area on which once stood the buildings of the first Croydon Aerodrome (the 'Plough Lane' aerodrome) which was demolished in 1928. The name comes from Roundshaw Park on the edge of the site, itself named from a round 'shaw' or grove of trees, which is still a feature. The estate is a compact one, housing some 8,000 people. It was begun in 1965, with the first tenants moving in during August 1967. Dwellings on the estate are heated from a communal boiler house. It has its own shops, a library, and a community centre; and formerly had its own public house. Roundshaw is often used as a setting for the ITV drama, The Bill.

A church, opened in 1981, is used by both the Church of England and the Free Churches, which, before it was built, had collaborated in a churchless religious venture known as the 'Roundshaw Experiment'. A cross set up outside the church is made from a four-bladed propeller, or airscrew, obtained through the Croydon Airport Society. The history of the site was commemorated in various ways, including the naming of roads, and Instone Close, the high-rise block of flats demolished in November 2000, after aircraft, personalities, and firms linked with aviation. One of the schools on the site has been renamed in recent years the Amy Johnson Primary School, after the famous aviator of the 1930s and 40s, the first woman to fly solo to Australia, whose epic flight began at Croydon in May 1930.