The Ibicuí River (Portuguese, Rio Ibicuí[1]) (Portuguese pronunciation: [ibikuˈi]) is a river in Rio Grande do Sul state of southern Brazil. The Ibicuí is 290 km in length, and is the main tributary of the Uruguay River. It is formed by the confluence of the Ibicuí-Mirim River and Santa Maria River at the city of Cacequi.