| Country: | Wales |
| Welsh Name: | Llanllwchaearn |
| Coordinates: | 52.5198°N -3.3172°W |
| Official Name: | Llanllwchaiarn |
| Population: | 848 |
| Population Ref: | (2011)[1] |
| Unitary Wales: | Powys |
| Lieutenancy Wales: | Powys |
| Community Wales: | Newtown and Llanllwchaiarn |
| Constituency Westminster: | Montgomeryshire |
| Post Town: | NEWTOWN |
| Postcode District: | SY16 |
| Postcode Area: | SY |
| Dial Code: | 01686 |
| Os Grid Reference: | SO107921 |
Llanllwchaiarn or Llanllwchaearn (in Welsh ɬanɬuː′χaɨarn/) in Welsh) is a village on the outskirts of Newtown in Powys, Wales. It forms part of the community of Newtown and Llanllwchaiarn.
Aberbechan Hall was a Tudor mansion in the eastern part of the parish demolished in 1870.
The wards of Llanllwchaiarn North and Llanllwchaiarn West elect up to four councillors to Newtown and Llanllwchaiarn Town Council.[2]