Ó Cearbhalláin
Ó CEARBHALLÁIN—I—O Carowlane, O Carolan, Carolan, Carrolan, &c.; 'descendant of Cearbhallán' (diminutive of Cearbhall); a well-known Ulster surname; formerly common in Donegal, Tyrone, Monaghan and Cavan; also in Meath. There are probably several distinct families of the name. To be distinguished from Ó Coirealláin, which see.
Alphabetical Index to Irish Surnames