Castelfiorentino is a city and comune in the Metropolitan City of Florence, Tuscany, central-northern Italy, located between Florence, Pisa and …Castelfiorentino is a city and comune in the Metropolitan City of Florence, Tuscany, central-northern Italy, located between Florence, Pisa and Siena. 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.