The patroness of Fiumedinisi is Our Lady of the Annunciation, celebrated on 25 March. The sanctuary dedicated to her, the town's mother church, dates from the 12th century and was rebuilt by King Charles III of Sicily, who expressed his «royal gratitude» to Fiumedinisi in a message still legible today on a plaque on the church's main façade.
Among the town's other religious buildings is the church of San Pietro, likewise from the 11th-12th century. The municipal territory also holds the Belvedere Castle, a Norman fortification from the same period.
