Avisaurus (meaning "bird lizard") is a genus of enantiornithine avialan from the Late Cretaceous of North America.

[1] Avisaurus archibaldi was discovered in the Late Cretaceous Hell Creek Formation of North America (Maastrichtian, from c.70.6-66 million years ago), making it one of the last enantiornithids.

[2] Avisaurus gloriae Varricchio and Chiappe 1995,[3] discovered in the late Campanian Upper Two Medicine Formation of Glacier County, Montana, USA, was renamed Gettyia by Atterholt et al.

[3] This genus belongs to the enantiornithine family Avisauridae, which also contains similar animals from South America such as Soroavisaurus, Neuquenornis and Intiornis.

[6] Further discoveries and further study by Chiappe showed that all of the material belonged to enantiornithine birds, and PVL 4690 was given its own genus Soroavisaurus.