Castelfiorentino is a city and comune (municipality) in the Metropolitan City of Florence, Tuscany, central-northern Italy, located between Florence, Pisa (45 km) and Siena (55 km). The population numbers approximately 20,000 inhabitants. It is part of Valdelsa. Castelfiorentino borders the following municipalities: Certaldo, Empoli, Gambassi Terme, Montaione, Montespertoli and San Miniato.