| Country: | Wales |
| Official Name: | Pen-Llyn |
| Coordinates: | 53.3124°N -4.4763°W |
| Community Wales: | Bodedern |
| Unitary Wales: | Anglesey |
| Constituency Welsh Assembly: | Ynys Môn |
| Constituency Westminster: | Ynys Môn |
| Post Town: | Caergybi |
| Postcode District: | LL65 |
| Dial Code: | 01407 |
| Os Grid Reference: | SH 3513 8235 |
Pen-Llyn is a hamlet in the community of Bodedern, Anglesey, Wales, between Bodedern and Llanddeusant, some 4.5 miles from Valley.[1] Llyn Llywenan, the largest natural lake on the island is nearby.