Amanasaurus (meaning "rain lizard") is a genus of silesaurid dinosauriform from the Late Triassic Santa Maria Supersequence of Rio Grande do Sul, Brazil.

CAPPA/UFSM 0375, a distal left femur belonging to a larger individual from the same locality, was also referred to Amanasaurus.

[1] In 2023, Müller & Garcia described Amanasaurus nesbitti as a new genus and species of silesaurid based on these remains.

Similar to a number of recent studies, these taxa, along with other "traditional" silesaurids, are treated as a paraphyletic grade of ornithischians.

The results of their phylogenetic analyses are shown in the cladogram below:[1] Saurischia Soumyasaurus Asilisaurus Gamatavus Lutungutali Technosaurus Sacisaurus Amanasaurus Ignotosaurus Eucoelophysis Pisanosaurus Laquintasaura