Irlanda
Países del mundo
O
- (Kerry) Oughtiv
- (County Cork) Oldcourt
- (County Cork) Old Port House
- (County Cork) Oysterhaven
- (Clare) O’Callaghansmills
- (County Galway) Oghil
- (Wicklow) Oldbridge
- (Mayo County) Oldcastle
- (County Cork) Oldchapel
- (Wexford) Oldcourt
- (Wicklow) Oldcourt
- (County Carlow) Oldleighlin
- (Wexford) Old Ross
- (Laois) Old Town
- (County Donegal) Old Town
- (County Cork) Old Twopothouse Cross Roads
- (County Galway) Onaght
- (Roscommon) Oran
- (Meath) Oristown
- (County Galway) Ormond View
- (Uíbh Fhailí) Oughter
- (County Galway) Ourtnagapple
- (County Cork) Ovens
- (Mayo County) Owenduff
- (Mayo County) Ooghwee
- (Mayo County) Owenboy
- (Clare) Oughtdarra
- (County Galway) Oatquarter
- (Sligo) Owenykeevan
- (Clare) Oatfield