| Castet-Arrouy | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Castet-Arrouy (Gers).svg |
| Arrondissement: | Condom |
| Canton: | Lectoure-Lomagne |
| Insee: | 32085 |
| Postal Code: | 32340 |
| Mayor: | Robert Laffourcade[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Lomagne Gersoise |
| Coordinates: | 43.9806°N 0.7167°W |
| Elevation M: | 107 |
| Elevation Min M: | 87 |
| Elevation Max M: | 180 |
| Area Km2: | 8.04 |
Castet-Arrouy is a commune in the Gers department in southwestern France.
The river Auroue flows north through the commune and forms part of its northeastern border.
The Church of Saint Blandine is the main church of Castet-Arrouy. The choir was painted with murals by artist Paul Noël Lasseran in 1901.