Ó Doibhilin is an Irish Gaelic surname, a patronymic form meaning "descendant of Doibhilin." The name originated in Ireland and is found in historical records primarily in the northern counties, particularly Donegal and Tyrone. The personal name Doibhilin is believed to derive from the Gaelic element dobhail, meaning "unlucky" or "ill-fated." This etymology may indicate a folk-belief origen, where a name with a potentially negative meaning was chosen as a protective measure to ward off evil or deflect misfortune. However, alternative interpretations also link it to an old Gaelic term for a small, stout person. The surname is typically anglicized as Devlin, which is the more common modern form encountered in Ireland and the Irish diaspora. The Ó Doibhilin family belonged to the Cenél Conaill kindred, a Sept of the Uí Néill's northern branch, which placed them among the powerful families of Donegal. In medieval times, the Ó Doibhilins were noted as physicians, settled in the barony of Tír Enna and the Raphoe area. They held hereditary medical knowledge and served as physicians to the O'Donnells, counts of Tyrconnell. This surname exemplifies the common Irish patronymic structure: the prefix Ó (meaning "grandson" or "descendant") indicates descent from a male ancestor. Over the centuries, it often lost the accent or shorthand under anglicization. Despite the Gaelic form being less frequently used in modern census returns than Devlin, academic interest in Irish genealogy has brought attention to such original forms in historical documents and surname registers. Meaning: descendant of DoibhilinOrigin: Irish GaelicType: patronymic surnameAnglicization: Devlin