Cheapside is a street in the City of London, the historic and modern financial centre of London, England, which forms part of the A40 London to Fishguard road. It links St. Martin's Le Grand with Poultry. Near its eastern end at Bank junction, where it becomes Poultry, is Mansion House, the Bank of England, and Bank station. To the west is St. Paul's Cathedral, St Paul's tube station and square.

St. Martin's Le Grand is a former liberty within the City of London, and is the name of a street north of Newgate Street and Cheapside and south of Aldersgate Street. It forms the southernmost section of the A1 road. For many years St. Martin's Le Grand was "often used as a synonym for the chief postal authorities, as Scotland Yard is used to designate the police", the headquarters of the General Post Office having been there from 1829-1984.