Pienza Cathedral (Italian: Duomo di Pienza; Concattedrale di Santa Maria Assunta) is a Roman Catholic cathedral dedicated to the Assumption of the Virgin Mary in Pienza, in the province of Siena, Italy.
From 1462 the episcopal seat of the Diocese of Pienza, then since 1773 of the Diocese of Chiusi-Pienza, it has been since 1986 a co-cathedral in the Diocese of Montepulciano-Chiusi-Pienza.