| Official Name: | San Martín |
| Pushpin Map: | Argentina Greater Buenos Aires |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in Greater Buenos Aires |
| Pushpin Mapsize: | 240 |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Buenos Aires |
| Subdivision Type2: | Partido |
| Subdivision Name2: | General San Martín |
| Population Total: | 28,339 |
| Coordinates: | -34.5667°N -90°W |
| Elevation M: | 28 |
| Postal Code Type: | CPA Base |
| Postal Code: | B 1650 |
| Area Code: | +54 11 |
Ciudad del Libertador General Don José de San Martín, more commonly known as San Martín, is the administrative seat of General San Martín Partido in the urban agglomeration of Greater Buenos Aires.
The area is heavily urbanised and is home to numerous food processing industries, as well as to a large Peugeot-Citroën auto factory. The city is bordered to the north-east by the autonomous city of Buenos Aires.
The town is home to the Chacarita Juniors football club, champions of Argentina in Metropolitano 1969.