A bell tower is a tower that contains one or more bells, or that is designed to hold bells even if it has none. Such a tower commonly serves as part of a church, and will contain church bells, but there are also many secular bell towers, often part of a municipal building, an educational establishment, or a tower built specifically to house a carillon. Church bell towers often incorporate clocks, and secular towers usually do, as a public service.
The term campanile (/ - /,, also US: /-/, Italian: [kampaˈniːle]), deriving from the Italian campanile, which in turn derives from campana, meaning "bell", is synonymous with bell tower; though in English usage campanile tends to be used to refer to a free standing bell tower. A bell tower may also in some traditions be called a belfry, though this term may also refer specifically to the substructure that houses the bells and the ringers rather than the complete tower.