| Libertador General San Martín Department | |
| Native Name Lang: | es |
| Settlement Type: | Department |
| Mapsize: | 180px |
| Pushpin Map Caption: | Location of Libertador General San Martín Department in Argentina |
| Coordinates: | -26.5333°N -79°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Argentina |
| Subdivision Type1: | Province |
| Subdivision Name1: | Chaco Province |
| Established Title: | Established |
| Established Date: | 1934 |
| Seat Type: | Head town |
| Seat: | General José de San Martín |
| Unit Pref: | Metric |
| Area Total Km2: | 7,800 |
| Population Total: | 54,470 |
| Population Density Km2: | auto |
| Population Demonym: | Sanmartinense |
| Timezone1: | ART |
| Utc Offset1: | -3 |
| Postal Code: | H3509 |
| Area Code: | 03725 |
Libertador General San Martín is a department located on the north eastern border of Chaco Province in Argentina.
The provincial subdivision has a population of about 54,500 inhabitants in an area of 7,800 km2, and its capital city is General José de San Martín, which is located around 1,125 km from the Capital federal.
The department and its cabecera (capital) are named after José de San Martín, the General that led Argentina to victory over the Spanish Empire in the Argentine War of Independence.