| Marguestau | |
| Commune Status: | Commune |
| Arrondissement: | Condom |
| Canton: | Grand-Bas-Armagnac |
| Insee: | 32236 |
| Postal Code: | 32150 |
| Mayor: | Anthony Ferreira[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Grand-Armagnac |
| Coordinates: | 43.8858°N -0.0403°W |
| Elevation M: | 140 |
| Elevation Min M: | 101 |
| Elevation Max M: | 148 |
| Area Km2: | 3.21 |
Marguestau (in French pronounced as /maʁɡɛsto/) is a commune in the Gers department in southwestern France.