Bayannurosaurus is a non-hadrosauriform ankylopollexian ornithopod described in 2018 by Xu Xing.

It lived during the early Aptian period, being found in the Bayin-Gobi Formation of China.

[1] The genus includes the type species Bayannurosaurus perfectus.

It was a large iguanodontian, measuring up to 9 metres (30 ft) in total body length.

[1] The genus name Bayannurosaurus comes from Bayannur, the area where it was found, while the species name perfectus comes from the "perfect" preservation of the holotype specimen (IMMNH PV00001).