| Castillejo de Martín Viejo | |
| Settlement Type: | Municipality |
| Pushpin Map: | Spain |
| Pushpin Map Caption: | Location in Spain |
| Coordinates: | 40.7006°N -6.6456°W |
| Subdivision Type: | Country |
| Subdivision Name: | Spain |
| Subdivision Type1: | Community |
| Subdivision Name1: | Castile and León |
| Subdivision Type2: | Province |
| Subdivision Name2: | Salamanca |
| Subdivision Type3: | Comarca |
| Subdivision Name3: | Comarca de Ciudad Rodrigo |
| Subdivision Type4: | Subcomarca |
| Subdivision Name4: | Campo de Argañán |
| Leader Party: | People's Party |
| Leader Title: | Mayor |
| Leader Name: | Cándido Palacios Palacios |
| Area Total Km2: | 156 |
| Elevation M: | 672 |
| Population Density Km2: | auto |
| Population Demonym: | Castillejenses |
| Timezone1: | CET |
| Utc Offset1: | +1 |
| Timezone1 Dst: | CEST |
| Utc Offset1 Dst: | +2 |
| Postal Code Type: | Postal code |
| Postal Code: | 37592 |
| Area Footnotes: | [1] |
Castillejo de Martín Viejo is a municipality in the province of Salamanca, western Spain, part of the autonomous community of Castile and León. It is located from the city of Salamanca. it has a population of 227.