The Italian Catholic diocese of Ferentino existed until 1986, when it was united into the new diocese of Frosinone-Veroli-Ferentino.
In the time of Emperor Constantine Ferentino had its own bishop; but the first known by name is Bassus, present at Roman synods, 487 and 492-493. St. Redemptus (about 570) is mentioned in the Dialogues of Gregory the Great; and he also refers to a Bishop Boniface.
Other bishops are