The Metropolitan Green Belt is a statutory green belt around London, England. It comprises parts of Greater London, Berkshire, Buckinghamshire, Essex, Hertfordshire, Kent and Surrey, parts of two of the three districts of Bedfordshire and a small area in Copthorne, Sussex. As of 2017/18, Government statistics show the planning designation covered 513,860 hectares of land.

Greater London is the administrative area of London, England, which is coterminous with the London region. It contains 33 local government districts: the 32 London boroughs, which form a ceremonial county also called Greater London, and the City of London. The Greater London Authority is responsible for strategic local government across the region, and regular local government is the responsibility of the borough councils and the City of London Corporation. Greater London is bordered by the ceremonial counties of Hertfordshire to the north, Essex to the north-east, Kent to the south-east, Surrey to the south, and Berkshire and Buckinghamshire to the west.