[1] Together, the inner and outer boroughs form London, the capital city of the United Kingdom.

Under this classification, Outer London consists of the nineteen London boroughs of Barking and Dagenham, Barnet, Bexley, Brent, Bromley, Croydon, Ealing, Enfield, Greenwich, Harrow, Havering, Hillingdon, Hounslow, Kingston upon Thames, Merton, Redbridge, Richmond upon Thames, Sutton, and Waltham Forest.

Figures here are for the Office for National Statistics defined Outer London (in its 2001 limits), whose land area is 1,254 km2 (484 sq mi).

Figures before 1971 have been reconstructed by the Office for National Statistics based on past censuses in order to fit the 2001 limits.

Heathrow Airport and Croydon are the most significant locations for employment in Outer London.