The patron saints of Sarno are Our Lady of the Three Crowns, celebrated on 15 August in the 17th-century sanctuary dedicated to her, and Saint Michael the Archangel, co-patron, celebrated on 8 May.
Saint Michael is venerated in the imposing Duomo di Sarno, the co-cathedral named after him in the hamlet of Episcopio. The municipal territory also holds the Sanctuary of the Blessed Virgin Mary of Carmel at the Castle, dating from the 12th century, the Sanctuary of Santa Maria della Foce, the monumental 13th-century church of San Francesco d'Assisi and the 18th-century church of the Immaculate Conception.
