Cainnech of Aghaboe was a sixth-century Irish priest, missionary, and abbot who is recognized as one of the Twelve Apostles of Ireland. Born in Ulster, he studied at the monastic school in Clonard and became a close companion to Colmcille. His religious work spanned across Ireland and into Scotland, where he preached to the Picts and established several monastic sites. He is highly regarded for his learning and eloquence, particularly for his written commentary on the Gospels.