San Tammaro is a comune (municipality) in the Province of Caserta in the Italian region Campania, located about north of Naples and about west of Caserta.
San Tammaro borders the following municipalities: Capua, Casal di Principe, Casaluce, Frignano, Santa Maria Capua Vetere, Santa Maria la Fossa, Villa di Briano. The Royal Palace of Carditello is located in the communal territory.