Pirapó is a municipality of the western part of the state of Rio Grande do Sul, Brazil. The population is 2,254 (2020 est.) in an area of 295.01 km². The town is situated by the Ijuí River, close to its confluence with the Uruguay River, which forms the border with Argentina. It is located 563 km west of the state capital of Porto Alegre and northeast of Alegrete. The municipality would be partially flooded by the proposed Garabí Dam.