On
| Location | Locality | Coordinates (links to map & photo sources) |
OS grid reference |
| Onchan | Isle of Man | 54.17° N 04.46° W | SC3978 |
| Onecote | Staffordshire | 53.09° N 01.94° W | SK0455 |
| Onehouse | Suffolk | 52.19° N 00.95° E | TM0259 |
| Onen | Sir Fynwy (Monmouthshire) | 51.82° N 02.82° W | SO4314 |
| Onesacre | Sheffield | 53.43° N 01.56° W | SK2993 |
| Onibury | Shropshire | 52.40° N 02.80° W | SO4579 |
| Onich | Highland | 56.69° N 05.23° W | NN0261 |
| Onllwyn | Castellnedd Phort Talbot (Neath Port Talbot) | 51.77° N 03.68° W | SN8410 |
| Onneley | Shropshire | 52.98° N 02.37° W | SJ7543 |
| Onny | Shropshire | 52.41° N 02.82° W | SO441795 |
| Onslow Village | Surrey | 51.23° N 00.61° W | SU9749 |
| Onthank | East Ayrshire | 55.62° N 04.51° W | NS4240 |
Read more about this topic: List Of United Kingdom Locations: On-Oz