| Official Name: | Bayubas de Abajo |
| Settlement Type: | Municipality |
| Pushpin Map: | Spain Castile and León#Spain |
| Pushpin Map Caption: | Location in Spain |
| Subdivision Type: | Country |
| Subdivision Type1: | Autonomous community |
| Subdivision Name3: | Comunidad de villa y tierra de Berlanga |
| Area Total Km2: | 43 |
| Population Density Km2: | auto |
| Utc Offset: | +1 |
| Utc Offset Dst: | +2 |
Bayubas de Abajo is a municipality located in the province of Soria, Castile and León, Spain. According to the 2004 census (INE), the municipality has a population of 250 inhabitants.