| Llanwddyn | |
|---|---|
  Llanwddyn Location within Powys | |
| Area | 95.92 km2 (37.03 sq mi) |
| Population | 257 (2011) |
| • Density | 3/km2 (7.8/sq mi) |
| Principal area | |
| Country | Wales |
| Sovereign state | United Kingdom |
| Post town | Llanfyllin |
| Postcode district | SY22 |
| Police | Dyfed-Powys |
| Fire | Mid and West Wales |
| Ambulance | Welsh |
| UK Parliament | |
Llanwddyn () is a village and community in Montgomeryshire, Powys, Wales. The community is centred on the Lake Vyrnwy reservoir. The original Llanwddyn village, about 2 miles (3.2 km) northwest, was submerged when the reservoir was created in the 1880s.