| Official Name: | Villanueva de San Mancio, Spain |
| Subdivision Name3: | Villanueva de San Mancio |
| Area Total Km2: | 15.16 |
| Elevation M: | 744 |
| Population Density Km2: | auto |
| Utc Offset: | +1 |
| Utc Offset Dst: | +2 |
Villanueva de San Mancio is a municipality located in the province of Valladolid, Castile and León, Spain. According to the 2004 census (INE), the municipality had a population of 125 inhabitants.