| Château-Gaillard | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Château-Gaillard (Ain).svg |
| Arrondissement: | Belley |
| Canton: | Ambérieu-en-Bugey |
| Insee: | 01089 |
| Postal Code: | 01500 |
| Mayor: | Joël Brunet[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Plaine de l'Ain |
| Coordinates: | 45.97°N 5.3°W |
| Elevation M: | 230 |
| Elevation Min M: | 222 |
| Elevation Max M: | 253 |
| Area Km2: | 16.6 |
Château-Gaillard (in French pronounced as /ʃɑto ɡajaʁ/) is a commune in the eastern French department of Ain.
The river Albarine forms most of the commune's southern border.