O (South Dublin) Oldbawn (County Galway) Oranmore Oileán Ciarraí (Kildare) Old Kilcullen (Meath) Oldcastle (County Galway) Oughterard (Kildare) Oughterard (Louth) Omeath (Fingal County) Oldtown (Limerick City and County Council) Old Kildimo (Clare) O’Briensbridge (Wexford) Oilgate (Limerick City and County Council) Oola (Wexford) Oulart (County Monaghan) Oram (County Cork) O'Callagha Park (County Tipperary) Oakhampton (Mayo County) Oxford (Sligo) Old Town (Sligo) Ogham (Wicklow) Oghil Lower (Wicklow) Oghi Upper (County Carlow) Oldtown (Sligo) Oghambaun (Sligo) Oldrock (Sligo) Ogham (County Leitrim) Orcusconny (County Galway) Oileán Dá Bhranóg (County Galway) Oileán na Tuí (County Donegal) Owey Island 1 2 3