A bell tower is a tower which contains one or more bells, or which is designed to hold bells, even if it has none. In the European tradition, such a tower most commonly serves as part of a church and contains church bells. Modern bell towers often contain carillons.

The Italian term Campanile (/ˌkæmpəˈniːliː/; Italian pronunciation: [kampaˈniːle]), deriving from the word 'campana' meaning bell, is synonymous with 'bell tower'; in American English it tends to be used to refer to free standing bell towers.