John Chrysostom (349-407): Archbishop of Constantinople, was an important Early Church Father. He is known for his preaching and public speaking, his denunciation of abuse of authority by both ecclesiastical and political leaders, the Divine Liturgy of Saint John Chrysostom, and his ascetic sensibilities. The epithet Χρυσόστομος (Chrysostomos, anglicized as Chrysostom) means "golden-mouthed" in Greek and denotes his celebrated eloquence. Chrysostom was among the most prolific authors in the early Christian Church, exceeded only by Augustine of Hippo in the quantity of his surviving writings.

In the Roman Catholic Church he is recognized as a Doctor of the Church and commemorated on 13 September in the current General Roman Calendar and on 27 January in the older calendar