The diocese of Cloyne has its origins in the monastic settlement founded by St Colman in the 6th century. Cloyne was not one of the dioceses established at the Synod of Rathbreasail in 1111, but a bishop of Cloyne was ruling the diocese by 1148, which was recognised at the Synod of Kells in March 1152.

In 1326, Pope John XXII issued a papal bull