The patron saint of Sellano is Saint Severinus, celebrated on 8 June, in the 14th-century church dedicated to him, which preserves frescoes. The town's co-patron is the Blessed Giolo, an anchorite who lived between 1250 and 1315, whose remains are kept in Sellano.
The municipal coat of arms, recognised by decree of 28 January 1936, depicts Saint Michael the Archangel standing on a saddle («sella»), an image that offers a simple explanation for the origin of the town's name, built precisely on the saddle of a hill: the town indeed also preserves the church of San Michele Arcangelo, from the 17th century, likewise with frescoes. On the origin of the place name, historians are divided between two theories: the older one traces it to the Roman tribe of the gens Suilla or the Syllinates mentioned by Pliny, while other scholars trace it to the followers of Lucius Cornelius Sulla, who according to this version founded the town in 84 BC, after the Battle of Spoletium, during the first Roman civil war.
