| Piratini River | |
| Source1 Location: | Rio Grande do Sul state |
| Mouth: | Uruguay River |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
| Length: | 352km (219miles)[1] |
| Basin Size: | 5621km2 |
The Piratini River is a river of Rio Grande do Sul state in southern Brazil.