Irish Surnames Starting with O

Descendant of Lachtnáin (grey)

Descendant of Laocháin (small hero)

Descendant of Mathghamhna (bear)

Noble chief

Descendant of Meadhra (merry one)

Descendant of Meadhra (merry)

Descendant of Mocháin (early riser)

Descendant of Móráin (great one)

Champion

Descendant of Rabhartaigh (flood tide)

Descendant of Raghailligh (sociable)

Restless one

Hawk-like

Descendant of Siadhail (seed)

Dark-eyed

Descendant of Tuathail (people-mighty)

Of Norse origin (Orm's farm)