According to writer Aníbal Machado, this river is known to the amerindians as Uaimií and by the bandeirantes as Guaicuí, from which the name Barra do Guaicuí for the place where the Das Velhas empties into the São Francisco River. In Tupi "gwaimi" means "old" whereas in Uaimii the final "i" means "river". "Rio das Velhas" means "River of the old women".
