The Baptistery is divided from the main body of the Cathedral by an iron grille, according to the early Christian custom.

The octagonal design of the font is symbolic, with the number eight traditionally the number of the new life of grace. Made of soapstone, the font features symbolic representations of the graces received through baptism.
Grotesques at the foot of the font represent devils cast out by the grace of baptism.

The panels around the font represent three of the Evangelists: Mark, Luke and John, while the fourth panel depicts an angel holding the scroll on which the names of the children of God are inscribed.