| Vacacaí River | |
| Source1 Location: | Rio Grande do Sul state |
| Source1 Coordinates: | -30.7333°N -64°W |
| Mouth: | Jacuí River |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
The Vacacaí River (pronounced as /pt/) is a river of Rio Grande do Sul state in southern Brazil.