Jacui River
General data
- Name: Jacui River
- Water system: Lagoa dos Patos
- Water type: River
- Progression: Guaiba River -> Lagoa dos Patos -> Rio Grande Channel -> Atlantic Ocean -> Planet Earth
- Climates: Tropical
- Continents: South America
- Countries: Brazil
The Jacuí River (Portuguese pronunciation: [ʒakuˈi]) is a 723 km long river in Rio Grande do Sul state of southern Brazil. The Jacuí empties into the Guaíba River, an estuarine arm of the Lagoa dos Patos, a large coastal lagoon connected to the Atlantic Ocean.