| Porthdinllaen | |
|---|---|
 Porthdinllaen seen from Morfa Nefyn | |
  Porthdinllaen Location within Gwynedd | |
| Population | 2 |
| OS grid reference | SH276416 |
| Community | |
| Principal area | |
| Preserved county | |
| Country | Wales |
| Sovereign state | United Kingdom |
| Post town | Pwllheli |
| Postcode district | LL53 |
| Dialling code | 01758 |
| Police | North Wales |
| Fire | North Wales |
| Ambulance | Welsh |
| UK Parliament | |
| Senedd Cymru – Welsh Parliament | |
Porthdinllaen (in English sometimes Porth Dinllaen) is a small coastal village on the Llŷn Peninsula in the Dwyfor area of Gwynedd, Wales, built on a small promontory, and historically in Caernarfonshire. It is near the larger village of Morfa Nefyn.
It has been owned by the National Trust since 1994. With views across to Yr Eifl and Snowdonia, Porthdinllaen, with Nefyn and Morfa Nefyn, forms a 2-mile (3.2 km) bay. There are only about two dozen buildings at Porthdinllaen, with the Tŷ Coch Inn at the centre of the village.
Vehicular access to the village is restricted to residents with a car permit; visitors must walk across the beach from Morfa Nefyn or across the Nefyn & District Golf Club golf course on top of the headland, past the Iron Age hill fort.