Irish Surnames Starting with O

Descendant of Birn (warrior)

Descendant of Baoighill (vain pledge)

Descendant of Braonáin (sorrow)

Noble and strong

Descendant of Broin (raven)

Descendant of Ceallacháin (bright-headed)

Descendant of Cearbhaill (fierce warrior)

Descendant of Cathasaigh (vigilant)

Descendant of Cléirigh (clerk)

Descendant of Conaill (strong wolf)

Lover of hounds

Descendant of Comhraidhe (hound of the plain)

Descendant of Dálaigh (assembly frequenter)

Descendant of Dábhoireann (two Burrens)

Descendant of Deaghaidh (good luck)

Descendant of Díomasaigh (proud)

Descendant of Dochartaigh (hurtful)

World-mighty

Descendant of Donnchadh (brown warrior)

Descendant of Donnubháin (dark brown)

Descendant of Dubhda (dark)

Descendant of Eidirsceóil (intermediary)

Descendant of Dubháin (little dark one)

Dark wisdom

Descendant of Fearghail (man of valor)

Descendant of Flaithbheartaigh (bright ruler)

Descendant of Flannagáin (ruddy)

Descendant of Gallchobhair (foreign help)

Descendant of Gadhra (hunting dog)

Descendant of Gormáin (blue man)

Descendant of Grádaigh (noble)

Descendant of Ágáin (young)

Descendant of Ailgheasaigh (eager)

Descendant of Allmhuráin (stranger from beyond...

Descendant of Anluain (great hero)

Descendant of Eaghra (bitter)

Descendant of Airt (bear)

Descendant of Aonghusa (one choice)

Descendant of Uiginn (viking)

Descendant of Iomhair (bow warrior)

Descendant of Iarthlaigh (western lord)

Descendant of Catháin (warrior)

Descendant of Céin (ancient)

Descendant of Caoimh (gentle)

Descendant of Cinnéidigh (helmeted head)

Descendant of Láimhín (hand)

Calf herder

Descendant of Luain (warrior)