The baptistery dedicated to Saint John the Baptist (Battistero di San Giovanni), the patron saint of the city of Florence, is located in front of the Cathedral of Santa Maria del Fiore, in Piazza San Giovanni.

Initially it was located outside the city walls, but it was included with the cathedral in the walls built by Matilda of Canossa (« fourth circle »). It was originally surrounded by other buildings, like the palace of the archbishop, after demolished to create the current site.