| Surname & Modifiers | Title & First Name | Location | Parish |
|---|---|---|---|
| O'GARA | |||
| O'GARA | Revd D | Ballindenisk | kilmonoge |
| O'GARA | Revd Dominick | Ballindenisk | kilmonoge |
| OLDHAM | |||
| OLDAM | Richard | Rossmore | inchigeelagh |
| OLHAM | Richard | Rossmore | inchigeelagh |
| ORPEN | |||
| ORPUN Esq | Edward | Parkina | kilmocomoge |
| ORPEN Esq | Edward | Parkina | kilmocomoge |
| OUROUGH | |||
| OUROUGH | Philip | West Kilkinihin | kilnamanagh |
| OWENS | |||
| OWENS | Griffith | Menane | ardnageehy |
| OWENS | John | Kilcrohane | kilcrohane |