Orvieto is a city and comune in the Province of Terni, southwestern Umbria, Italy, situated on the flat summit of a large butte of volcanic tuff. The city rises dramatically above the almost-vertical faces of tuff cliffs that are completed by defensive walls built of the same stone.

The province of Terni is the smaller of the two provinces in the Umbria region of Italy, comprising one-third of both the area and population of the region. Its capital is the city of Terni. The province came into being in 1927, when it was carved out of the original unitary province of Umbria.