| Name | Position | Party | Constituency |
|---|---|---|---|
| Pádraig O'Sullivan | TD | Fianna Fáil | Cork North-Central |
| Olivia O'Sullivan | Councillor | Fine Gael | Limerick City North |
| Larry O'Toole | Councillor | Sinn Féin | Artane - Whitehall |
| Pat O'Toole | Councillor | Fianna Fáil | Ballymahon |
| Liona O'Toole | Councillor | Independent | Lucan |
| Sean O’Brien | Councillor | Unknown | Tullamore |
| Dermot O’Brien | Councillor | Unknown | Bray West |
| Paul O’Brien | Councillor | Labour | Wicklow |
| Niall O’Callaghan | Councillor | Unknown | Killarney |
| Shane O’Callaghan | Councillor | Unknown | Cork City South Central |
| Juliet O’Connell | Councillor | Labour | Dún Laoghaire |
| Maeve O’Connell | Councillor | Unknown | Stillorgan |
| Rory O’Connor | Councillor | Unknown | Bray West |
| Liam O’Connor | Councillor | Unknown | Carrigaline |
| William O’Leary | Councillor | Unknown | Fermoy |
| Tom O’Leary | Councillor | Unknown | Balbriggan |