| Country: | Wales |
| Official Name: | Llanfair-y-Cwmwd |
| Coordinates: | 53.1752°N -4.325°W |
| Cardiff Distance Mi: | 126.5 |
| Cardiff Distance Km: | 203.5 |
| London Distance Mi: | 211.4 |
| London Distance Km: | 340.2 |
| Community Wales: | Rhosyr |
| Unitary Wales: | Anglesey |
| Constituency Welsh Assembly: | Ynys Môn |
| Constituency Westminster: | Ynys Môn |
| Post Town: | Llanfair Pwllgwyngyll |
| Postcode District: | LL61 |
| Os Grid Reference: | SH 4470 6676 |
Llanfair-y-Cwmwd (or Llanfair-yn-y-Cwmwd) is a village in the community of Rhosyr, Anglesey, Wales, which is 126.5 miles (203.5 km) from Cardiff and 211.4 miles (340.2 km) from London.