This area near the Tiber was inhabited by the Etruscans and then by the Romans as testified by the remains of tombs, dobecotes, Roman villas, columns and ceramic artifacts.
The village is medieval, dating back to the time when, during the Barbarian invasions, the people sought refuge on high ground with protective fortresses. No trace remains of the first castle built at the dawn of the year one thousand by the Bovaccini Counts, feudal lords of Corbera and Montemarte. The castle was built in the eleventh century by the Counts of Bagnoregio, whose descendants later took the name of Monaldeschi.
In 1322 the castle was demolished by the city of Orvieto in a war against the Monaldesi who were Ghibellines, and therefore opponents of the pope.
Orvieto installed the Guelph family of the Orsini and the following year rebuilt the castle. But the Monaldeschi returned in 1329. In 1353, Civitella was invaded by one of the Prefects of Vico but that did not last long and it was returned to the Monaldeschi. The Monaldesi were still enemies of the Church, and in 1415, the Apostolic Chamber drove them out permanently.
In 1517 Leo X, son of Lorenzo the Magnificent, following the reduction of a debt renewed the concession of the fiefdom of Civitella d’Agliano to the City of Orvieto in “perpetual vicarage“.
Civitella was seriously damaged by Lanzichenecche troops in 1527. From 1564 it became a free tributary of the Church and remained in the Papal States until the unification of Italy.