| Olwen | Woman | Welsh Names |
| Owain | Man | Welsh Names |
| Owena | Woman | Welsh Names |
| Parry | Unisex | Welsh Names |
| Pasgen | Man | Welsh Names |
| Pembroke | Unisex | Welsh Names |
| Powell | Man | Welsh Names |
| Pritchard | Man | Welsh Names |
| Pugh | Unisex | Welsh Names |
| Pwyll | Man | Welsh Names |
| Raewyn | Woman | Welsh Names |
| Ragle | Unisex | Welsh Names |
| Reese | Unisex | Welsh Names |
| Rhian | Woman | Welsh Names |
| Rhianna | Woman | Welsh Names |
| Rhiannon | Woman | Welsh Names |
| Rhianu | Woman | Welsh Names |
| Rhodri | Man | Welsh Names |
| Rhonda | Woman | Welsh Names |
| Rhoslyn | Unisex | Welsh Names |