A city hall is the seat of municipal government, housing the headquarters offices of a city. It is usually the single principal building in the municipal government. If the municipal offices are split among different structures, one of which is above the others in the hierarchy of administration, then only that one is listed as the city hall in that city, unless all of the buildings are named or commonly referred to as city hall.

The headquarters function distinguishes a city hall from an ordinary municipal service office. A tax or welfare office operated by the city does not by that fact become the seat of its government.

For a dispersed headquarters, the highest building in the administrative hierarchy normally supplies the city-hall designation. The stated naming exception allows several buildings when all are named or commonly called city hall.