| Castelnau-de-Mandailles | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Castelnau-de-Mandailles 12.svg |
| Arrondissement: | Rodez |
| Canton: | Lot et Palanges |
| Insee: | 12061 |
| Postal Code: | 12500 |
| Mayor: | Sandra Sielvy[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 44.5367°N 2.8864°W |
| Elevation M: | 550 |
| Elevation Min M: | 360 |
| Elevation Max M: | 949 |
| Area Km2: | 35.87 |
Castelnau-de-Mandailles (pronounced as /fr/; oc|Castèlnau de Mandalhas) is a commune in the Aveyron department in southern France.