The Metropolitan Green Belt is a statutory green belt around London, England. It includes designated parts of Greater London and the surrounding counties of Bedfordshire, Berkshire, Buckinghamshire, Essex, Hertfordshire, Kent and Surrey in the South East and East of England regions.

Serves five purposes:

• to check the unrestricted sprawl of large built-up areas;
• to prevent neighbouring towns merging into one another;
• to assist in safeguarding the countryside from encroachment;
• to preserve the setting and special character of historic towns;
• to assist in urban regeneration, by encouraging the recycling of derelict and other urban land.

It covers 89% of Guildford borough.