| San Martín Department | |
| Native Name: | Departamento San Martín |
| Settlement Type: | Department |
| Coordinates: | -29.1833°N -95°W |
| Subdivision Type: | Country |
| Subdivision Name: | Argentina |
| Established Title: | Established |
| Seat Type: | Seat |
| Seat: | La Cruz |
| Leader Title: | Mayor |
| Unit Pref: | Metric |
| Area Total Km2: | 6,385 |
| Population Total: | 12,236 |
| Population Density Km2: | auto |
| Postal Code Type: | Postal Code |
| Postal Code: | W3346 |
| Area Code Type: | Area Code |
| Area Code: | 03772 |
San Martín Department is a department of Corrientes Province in Argentina.
The provincial subdivision has a population of about 12,236 inhabitants in an area of, and its capital city is La Cruz.