 O'Leary

O'Leary is an Irish name, and an anglicized version of the original Gaelic patronym Ó Laoghaire () or Ó Laoire

The Uí Laoghaire clan, today associated with the Uibh Laoghaire parish in County Cork, is considered by scholars to have originated in the early Middle Ages on the south-west coast, in the area of Ros Ó gCairbre (Rosscarbery), of which the O'Leary were hereditary lords.The Annals of Innisfallen (Dublin copy) records St. Fachtna's (Saint Fachanan) death in 600 AD as occurring in "O'Laeghaire of Ross i.e.