| Eifion | |
|---|---|
| Former constituency for the House of Commons | |
| 1885–1918 | |
| Seats | one |
| Created from | Caernarvonshire |
| Replaced by | Caernarvonshire |
Eifion was a parliamentary constituency in Caernarfonshire, Wales. It returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom, elected by the first past the post system.