The patron saint of Ferentillo is Saint Sebastian, celebrated on 20 January.
The town is dominated by the imposing presence of two fortresses which, from 1100, together with that of Umbriano, served as a bulwark defending the nearby abbey of San Pietro in Valle: it was built in 720 by Faroaldo II, Lombard Duke of Spoleto, who enlarged the church founded by the hermits Giovanni and Lazzaro in 535. Ferentillo's history always followed that of the abbey, whose fief tried to become independent both from the Duchy of Spoleto and from the Lateran Chapter, until it became a small State in 1484 by the will of Pope Innocent VIII.
In the hamlet of Precetto stands the church of Santo Stefano, developed over two floors between the 13th and 16th centuries, with frescoes attributed to the school of Perugino or to Iacopo Siculo (1559): its crypt, as long as the building and enriched with 15th-century frescoes, was long used as the municipal cemetery and today houses the famous Mummy Museum. In the hamlet of Lavalle, the largest in the municipality, stands the abbey itself, which holds a large 12th-century fresco with the well-known detail of Adam naming the animals.
