| O'Moore Place, Portlaoise | €90,000 | 19 |
| Oak Manor, Ballacollig | — | 11 |
| Oak Vale Meadows, Church Avenue | — | 5 |
| Oak Vale Meadows, Stradbally | €303,965 | 5 |
| Oak View, Ballacollig | — | 8 |
| Oakley Crescent, Graiguecullen | €231,000 | 13 |
| Oakley Grove, Graiguecullen | — | 11 |
| Oakview, Ballacollig | — | 7 |
| Odaly Terrace, Rathdowney | — | 6 |
| Old Knockmay Rd, Portlaoise | — | 5 |
| Oldtown, Abbeyleix | — | 6 |
| Olive Close, Fruithill Manor | — | 6 |
| Olive Crescent, Fruithill Manor | — | 33 |
| Omoore St, Mountmellick | €197,500 | 11 |
| Orchard Dr, Portarlington | — | 5 |
| ossory court, borris on ossory | — | 12 |
| Ossory Court, Borris in Ossory | €210,000 | 50 |
| Ossory Court, Borris-In-Ossary | — | 5 |
| The Oaks, Kilnacourt Woods | €136,000 | 27 |
| The Orchard, Ballylynan | — | 8 |
| The Orchard, Graigavern Lodge | — | 6 |
| The Orchard, Maryborough Village | — | 5 |