The Irish surname O'Hearn is an anglicized form of Gaelic Ó hEachthighearna meaning “descendant of Eachthighearna,” a personal name meaning ‘lord of horses’, from each ‘horse’ + tighearna ‘master, lord’. In Ireland, the name is most common in the southwest. Their territory was in the neighborhood of Sixmilebridge, County Clare. From here they migrated southwards to County Cork and Waterford. The first recorded spelling of the family name is shown to be that of Alan O'Hathern alias O'Hachierane, which was dated 1336 - 1347, who was the Bishop of Kerry.