The patron saint of Marianopoli is Saint Prosper the martyr, celebrated on the first Saturday of August, in the mother church dedicated to him, built in the 18th century by the baronial family: his relics were most likely transferred from the same family's palace in Catania to precisely this church, which was raised to parish status in 1805 under the title of Maria Santissima Addolorata.
The town also venerates the Signore di Bilìci, an ancient wooden crucifix believed to be thaumaturgic, perhaps from the 16th century, kept in the sanctuary dedicated to him, in the former fief of Castel Bilìci: his main feast is celebrated on 3 May. Marianopoli's territory, inhabited since prehistoric times, also hosts the archaeological sites of Monte Castellazzo, identified by scholars with ancient Mytistraton, a city allied with Carthage destroyed by the Romans during the Punic Wars, and of Balate-Valle Oscura, whose finds, brought to light by the Superintendency of Agrigento between 1977 and 1984, are today displayed in the town's ethnographic museum.
