Kelmayisaurus (meaning "Karamay lizard") is an extinct genus of allosauroid theropod dinosaur from the Early Cretaceous.

It was roughly 10–12 meters (33–39 feet) long and its name refers to the petroleum-producing city of Karamay in the Xinjiang province of western China near where it was found.

The specimen was found during the early 1970s in the Lianmuqin Formation of the Tugulu Group, dating to the Valanginian-Albian stages between 140 and 100 million years ago.

[2] A supposed second species, K. "gigantus", was mentioned in a popular book as being a 21-meter (69 foot) long vertebral column from the Middle Jurassic Shishugou Formation.

[7][8] However, Kelmayisaurus is diagnosable by the form and presence of a deeply inset accessory groove on the lateral side of the dentary, the main toothbearing bone of the lower jaw.