The patron saint of Acquaviva delle Fonti is Our Lady of Constantinople, whose patronal feast is held over four days culminating on the first Tuesday of September. The town's co-patrons are Saint Eustace, venerated in the cathedral dedicated to him and celebrated on the first Tuesday of March, and Saint Sebastian, on 20 May.
Starting from the week before the feast, the image of the Virgin is carried in procession over seven days through the town's seven parishes, in what is called the peregrinatio Mariae; on Sunday morning, after the celebration, the rite of the Enthronement is held. The town also holds the church of Santa Maria Maggiore and that of Santa Lucia.
