| Castéra-Lou | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Castéra-Lou (65).svg |
| Arrondissement: | Tarbes |
| Canton: | Les Coteaux |
| Insee: | 65133 |
| Postal Code: | 65350 |
| Mayor: | Sabine Cha[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Coteaux du Val-d'Arros |
| Coordinates: | 43.3236°N 0.1467°W |
| Elevation M: | 300 |
| Elevation Min M: | 231 |
| Elevation Max M: | 332 |
| Area Km2: | 4.82 |
Castéra-Lou (pronounced as /fr/; oc|Lo Casterar) is a commune in the Hautes-Pyrénées department in south-western France.