Weewarrasaurus is a genus of ornithopod dinosaur from the Late Cretaceous of the Griman Creek Formation near Lightning Ridge, in New South Wales, Australia.

[2] They found the specimen in a mine at the Wee Warra geologic locality of the Griman Creek Formation, near the town of Lightning Ridge, New South Wales, Australia during a routine mining run, and it was broken during excavation.

[2] Bell and colleagues later named it as a new genus and species in a study published on December 4, 2018, which reviewed the ornithopod fossil record for the Griman Creek Formation, which includes the mine.

The opal banding on the fossil was used to confirm that both parts of the dentary, which do not form a continuous sequence, were from the same individual.

It was found in the Holden's locality on the Three Mile opal field, also near Lightning Ridge and part of the Griman Creek Formation.