| San Andrés Yaá | |
| Settlement Type: | Municipality and town |
| Pushpin Map: | Mexico |
| Pushpin Label Position: | above |
| Pushpin Map Caption: | Location in Mexico |
| Subdivision Type: | Country |
| Subdivision Name: |  Mexico |
| Subdivision Type1: | State |
| Subdivision Name1: | Oaxaca |
| Area Total Km2: | 33.17 |
| Population As Of: | 2005 |
| Population Total: | 378 |
| Timezone: | Central Standard Time |
| Utc Offset: | -6 |
| Timezone Dst: | Central Daylight Time |
| Utc Offset Dst: | -5 |
| Coordinates: | 17.3°N -105°W |
San Andrés Yaá is a town and municipality in Oaxaca in south-western Mexico. The municipality covers an area of 33.17 km2. It is part of the Villa Alta District in the center of the Sierra Norte Region.
As of 2005, the municipality had a total population of 378.[1]