| Official Name: | Espeja de San Marcelino |
| Settlement Type: | Municipality |
| Coordinates: | 41.8025°N -3.2219°W |
| Pushpin Map: | Spain Castile and León#Spain |
| Pushpin Map Caption: | Location in Spain. |
| Subdivision Name1: | Castile and León |
| Subdivision Name2: | Soria |
| Subdivision Name3: | Espeja de San Marcelino |
| Area Total Km2: | 71 |
| Elevation M: | 1032 |
| Population Density Km2: | auto |
| Utc Offset: | +1 |
| Utc Offset Dst: | +2 |
Espeja de San Marcelino 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 238 inhabitants.