| San Justo Department | |
| Native Name: | Departamento San Justo |
| Native Name Lang: | es |
| Settlement Type: | Department |
| Mapsize: | frameless |
| Coordinates: | -31.4333°N -66°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Argentina |
| Subdivision Type1: | Province |
| Established Title: | Foundation |
| Seat Type: | Capital |
| Seat: | San Francisco |
| Unit Pref: | Metric |
| Area Total Km2: | 13677 |
| Population Total: | 190182 |
| Population Density Km2: | auto |
| Population Blank1 Title: | Pop. change |
| Population Blank1: | +7.63% |
| Timezone1: | ART |
| Utc Offset1: | -3 |
| Postal Code Type: | Postal code |
| Postal Code: | X2400 |
| Area Code Type: | Dialing code |
| Area Code: | 03564 |
| Blank Name Sec1: | Distances to |
| Blank Info Sec1: | |
| Blank1 Info Sec1: | 610km (380miles) |
| Blank2 Name Sec1: | Córdoba |
| Blank2 Info Sec1: | 209km (130miles) |
San Justo Department is a department of Córdoba Province in Argentina.
The provincial subdivision has a population of about 190,182 inhabitants in an area of 13,677 km2, and its capital city is San Francisco, which is located around 670 km from Buenos Aires. The department is home to Mar Chiquita, the largest inland body of water in Argentina.