Riograndia is an extinct genus of tritheledontid cynodonts from the Late Triassic of South America. The type and only species is Riograndia guaibensis. Remains have been found in the Caturrita Formation of the geopark of Paleorrota. It was a small non-mammalian cynodont, with several advanced features also present in mammals. Several specimens of Riograndia guaibensis have been found in the towns of Candelária and Faxinal do Soturno in the Caturrita Formation. The genus defines the Riograndia Assemblage Zone.
