Aghadoe Cathedral was a church that may have been the seat of a bishop at Aghadoe, Ireland (later joined with the Bishopric of Ardfert). The now ruined cathedral overlooks the Lakes of Killarney from Aghadoe, a few miles from Killarney. Aghadoe may have been the site of a church as early as the seventh century, but extant remains are of a stone structure built in the eleventh and twelfth centuries.