| Caulnes | |
| Native Name: | Kaon |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason de la ville de Caulnes (Côtes-d'Armor).svg |
| Coordinates: | 48.2897°N -2.1536°W |
| Insee: | 22032 |
| Postal Code: | 22350 |
| Arrondissement: | Dinan |
| Canton: | Broons |
| Mayor: | Marina Le Moal[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Dinan Agglomération |
| Elevation Min M: | 46 |
| Elevation Max M: | 133 |
| Area Km2: | 31.36 |
Caulnes (pronounced as /fr/; ; Gallo: Caunn) is a commune in the Côtes-d'Armor department of Brittany in northwestern France.
Caulnes has an oceanic climate (Köppen climate classification Cfb). The average annual temperature in Caulnes is . The average annual rainfall is with November as the wettest month. The temperatures are highest on average in August, at around, and lowest in January, at around . The highest temperature ever recorded in Caulnes was on 5 August 2003; the coldest temperature ever recorded was on 2 January 1997.
Inhabitants of Caulnes are called Caulnais in French.