| Saint-Denis-d'Authou | |
| Arrondissement: | Nogent-le-Rotrou |
| Canton: | Nogent-le-Rotrou |
| Image Coat Of Arms: | Blason ville fr Saint-Denis-d'Authou (Eure-et-Loir).svg |
| Insee: | 28331 |
| Postal Code: | 28480 |
| Commune: | Saintigny |
| Coordinates: | 48.3453°N 0.9875°W |
| Elevation M: | 238 |
| Elevation Min M: | 174 |
| Elevation Max M: | 286 |
| Area Km2: | 22.23 |
| Population: | 465 |
| Population Date: | 2019 |
| Population Footnotes: | [1] |
Saint-Denis-d'Authou (in French pronounced as /sɛ̃ dəni dotu/) is a former commune in the Eure-et-Loir department in northern France. On 1 January 2019, it was merged into the new commune Saintigny.[2]