| Treffiagat | |
| Native Name: | Triagad |
| Commune Status: | Commune |
| Coordinates: | 47.8044°N -4.2619°W |
| Elevation Min M: | -1 |
| Elevation Max M: | 26 |
| Insee: | 29284 |
| Postal Code: | 29730 |
| Arrondissement: | Quimper |
| Canton: | Pont-l'Abbé |
| Mayor: | Nathalie Carrot-Tanneau[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Pays Bigouden Sud |
| Area Km2: | 8.10 |
Treffiagat (in French pronounced as /tʁefjaɡat/;), also known as Treffiagat-Léchiagat, is a commune in the Finistère department of Brittany in north-western France.
Inhabitants of Treffiagat are called in French Treffiagatistes.