| Type: | municipality |
| Official Name: | Onzonilla, Spain |
| Subdivision Type: | Country |
| Subdivision Name: | Spain |
| Subdivision Name3: | Onzonilla |
| Area Total Km2: | 21 |
| Population Density Km2: | auto |
| Utc Offset: | +1 |
| Utc Offset Dst: | +2 |
Onzonilla is a municipality located in the province of León, Castile and León, Spain. At the 2011 census (INE), the municipality had a population of 1,761 inhabitants.