Terence Albert O'Brien was an Irish Dominican priest and the Roman Catholic Bishop of Emly who lived from 1600 to 1651. Born into the Gaelic nobility of County Limerick, he joined the Dominican Order and eventually rose to become a provincial leader before his consecration as bishop. During the Cromwellian conquest of Ireland, he supported the Catholic Confederation and advocated for resistance during the Siege of Limerick. Following the city's surrender, he was executed by the New Model Army, an act that led to his recognition as a martyr.