Guildhall is a municipal building in the Moorgate area of the City of London, England. It is off Gresham and Basinghall streets, in the wards of Bassishaw and Cheap. The current building dates from the 15th century; however documentary evidence suggests that a guildhall had existed at the site since at least the early 12th century. The building has been used as a town hall for several hundred years, and is still the ceremonial and administrative centre of the City of London and its Corporation. It should not be confused with London's City Hall, the administrative centre for Greater London. The term "Guildhall" refers both to the whole building and to its main room, which is a medieval great hall. It is a Grade I-listed building.

Moorgate was one of the City of London, England's northern gates in its defensive wall, the last to be built. The gate took its name from the Moorfields, an area of marshy land that lay immediately north of the wall.