| Piriac-sur-Mer | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Piriac-sur-Mer (Loire-Atlantique).svg |
| Arrondissement: | Saint-Nazaire |
| Canton: | Guérande |
| Insee: | 44125 |
| Postal Code: | 44420 |
| Mayor: | Emmanuelle Dacheux[1] |
| Term: | 2023 - 2026 |
| Intercommunality: | CA Presqu'île de Guérande Atlantique |
| Coordinates: | 47.3808°N -2.545°W |
| Elevation M: | 3 |
| Elevation Min M: | 0 |
| Elevation Max M: | 36 |
| Area Km2: | 12.37 |
Piriac-sur-Mer (in French pronounced as /piʁjak syʁ mɛʁ/, literally Piriac on Sea; Breton: Penc'herieg) is a commune in the Loire-Atlantique department in western France.