| Named By: | J. F. Bonaparte, J. Ferigolo, and A. M. Ribeiro in 1999 |
| Time Period: | Late Triassic, 216.5-212 Ma |
| Location: | Brazil |
| Size: | Roughly 1.8 meters long |
| Diet: | Uncertain |
| Fossil(s): | Almost complete and articulated post cranial skeleton and an almost complete hind limb |
| Classification: | | Chordata | Reptilia | Dinosauria | Saurischia | Sauropodomorpha | Guaibasauridae | |
Guaibasaurus is an extinct genus of basal dinosaur known from the Triassic of Rio Grande do Sul, southern Brazil.