Ó Duilleáin
Ó DUILLEÁIN—I—O Dullaine, O Dyllane, Dillane, (Dillon); an attenuated form of Ó Dalláin, which see; common in Kerry, Limerick, Clare and Galway, but often disguised under the anglicised form of Dillon.
Alphabetical Index to Irish Surnames