The cathedral basilica of Santa Maria Assunta is the main place of Catholic worship in Orvieto, in the province of Terni.
The construction of the church was started in 1290 at the behest of Pope Nicholas IV with the intention of creating a single large cathedral for the city to replace the two churches that pre-existed on the square. Designed in the Romanesque style by an unknown artist, the construction was then entrusted to various architects.