| Official Name: | San Martín de Trevejo, Spain |
| Settlement Type: | Municipality |
| Pushpin Map: | Spain |
| Pushpin Relief: | 1 |
| Pushpin Label Position: | none |
| Pushpin Map Caption: | San Martín de Trevejo within Spain |
| Coordinates: | 40.2167°N -54°W |
| Subdivision Type: | Country |
| Subdivision Name: | Spain |
| Subdivision Type1: | Autonomous community |
| Subdivision Name1: | Extremadura |
| Subdivision Type2: | Province |
| Subdivision Name2: | Cáceres |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | San Martín de Trevejo |
| Leader Title: | Alcalde |
| Leader Name: | Máximo Gaspar Carretero (PSOE) |
| Area Total Km2: | 23.82 |
| Elevation M: | 796 |
| Population Density Km2: | auto |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Website: | http://www.sanmartindetrevejo.es |
San Martín de Trevejo (Sa Martín de Trevellu) is a municipality (municipio) located in the province of Cáceres, Extremadura, Spain. According to the 2008 census (INE), the municipality has inhabitants.
Locally, manhegu (or mañegu) is spoken, a linguistic variety of the Fala language, which is different from both Spanish and Portuguese, but closer to the second.