Historically the diocese covered a large area north of the Thames and bordered the dioceses of Norwich and Lincoln to the north and west. The present diocese covers and 17 London boroughs, covering most of Greater London north of the River Thames and west of the River Lea. This area covers nearly all of the historic county of Middlesex. It includes the City of London in which lies its cathedral, St Paul's, and also encompasses Spelthorne which was formerly in Middlesex but is now part of Surrey.
The suffragan See of Stepney was created in 1895, Kensington in 1901, Willesden in 1911, and Edmonton in 1970. The suffragan See of Marlborough existed from 1888 to 1918, and the See of Islington from 1898 to 1923.
The diocese is divided into five episcopal areas, each of which is the particular responsibility of one of the diocese's suffragan bishops. It is further divided into archdeaconries and deaneries, as shown below.