| Name | Meaning | Details |
|---|---|---|
| Oakley | From The Oak Tree Field | View Details |
| Oburu | Ash | View Details |
| Oleander | Evergreen Tree | View Details |
| Olive | Olive Or From The Olive Tree | View Details |
| Orinda | Pine Trees | View Details |
| Ornella | Flowering Ash Tree | View Details |
| Orville | Golden Town | View Details |
| Overton | From The Riverbank Town | View Details |
| Owen | The Yew Tree Or Youth | View Details |
| Park | Cypress Tree | View Details |
| Paton | "From Paccas Town" | View Details |
| Paxton | "From Paccs Town" | View Details |
| Payton | "From Paccas Town" | View Details |
| Pelton | "From The Town Of Peolas Barrow" | View Details |
| Peri | Dweller By The Pear-tree | View Details |