The municipality is formed by the municipal seat of Montalcino and the towns and villages (frazioni) of Camigliano, Castelnuovo dell'Abate, Montisi, San Giovanni d'Asso, Sant'Angelo in Colle, Sant'Angelo Scalo and Torrenieri. Other notable villages include Argiano, La Croce, Lucignano d'Asso, Monte Amiata Scalo, Montelifré, Monterongriffoli, Pieve a Pava, Pieve a Salti, Poggio alle Mura, Tavernelle, Vergelle and Villa a Tolli.
