| Lago Buenos Aires | |
| Settlement Type: | Department |
| Subdivision Type: | Country |
| Subdivision Name: |  Argentina |
| Subdivision Type1: | Province |
| Subdivision Name1: | Santa Cruz |
| Seat: | Perito Moreno |
| Population Total: | 6223 |
| Area Total Km2: | 28609 |
Lago Buenos Aires Department is a department in Santa Cruz Province, Argentina. It has a population of 6,223 (2001) and an area of 28,609 km2. The seat of the department is in Perito Moreno.