| Settlement Type: | Municipality |
| Official Name: | San Xoán de Río |
| Pushpin Map: | Spain |
| Pushpin Map Caption: | Location in Spain |
| Subdivision Type: | Country |
| Subdivision Name: |  Spain |
| Subdivision Type1: | Autonomous community |
| Subdivision Type2: | Province |
| Subdivision Type3: | Comarca |
| Subdivision Name3: | Terra de Trives |
| Area Total Km2: | 61.1 |
| Area Footnotes: | [1] |
| Elevation M: | 875 |
| Population Density Km2: | auto |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Leader Title: | Mayor |
| Leader Name: | Luis Castro |
| Leader Party: | PSdeG-PSOE |
San Xoán de Río is a municipality in the province of Ourense, in the autonomous community of Galicia, Spain. It belongs to the comarca of Terra de Trives. It is named after Saint John (Galician: San Xoán), the local patron. The village of Domecelle is located within the municipality.