| Settlement Type: | Municipality |
| Flag Size: | 150 |
| Subdivision Type: | Country |
| Subdivision Name: | Spain |
| Subdivision Type1: | Autonomous community |
| Subdivision Name1: | Castile and León |
| Subdivision Type2: | Province |
| Subdivision Name2: | Salamanca |
| Subdivision Type3: | Comarca |
| Subdivision Name3: | Sierra de Francia |
| Population Density Km2: | auto |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Leader Title: | Mayor |
| Postal Code Type: | Postal code |
| Official Name: | San Martín del Castañar |
| Postal Code: | 37659 |
| Leader Name: | Alfonso Buenaventura Calvo González |
| Leader Party: | PSOE |
| Area Footnotes: | [1] |
| Area Total Km2: | 16 |
| Elevation M: | 834 |
| Coordinates: | 40.5231°N -6.0647°W |
San Martín del Castañar is a municipality located in the province of Salamanca, Castile and León, Spain. As of 2016 the municipality has a population of 226 inhabitants.[2]
San Martin has a major tourist activity in relation to the size of the municipality, especially at Easter and summer holidays. Saint festivities are held in August, they started the 9th and they usually last about 5 days.
Its main attractions are its castle, with a cemetery in the inner part, and the bullring (according to some sources, the second oldest in Spain).
Other remarkable places are the river and its surroundings; the church; the square; fountains or "pylons"; half-timbered houses; driveways; roads and the bakery, the only one in the village, in which "perronillas", assortment of pastries, muffins and “hornazos” are made by hand.