Quetecsaurus (meaning "fire lizard", from the Milcayac word "quetec"[1]) is a genus of titanosaurian sauropod dinosaur known from the Late Cretaceous of the southern Mendoza Province, western Argentina.

It is known solely from the holotype, a partial skeleton found in close association that includes a postorbital, teeth, the atlas, a rear cervical vertebra, an incomplete dorsal vertebra, a rear caudal centrum, dorsal ribs, a coracoid, five metacarpals and fragments of a humerus, radius and ulna.

Like lognkosaur titanosaurs, it possess lateral expansions on the neural spines of its rear cervical vertebra, however they are incipient and relatively reduced.

Quetecsaurus was assigned to the Titanosauria, and considered to be most closely related to Mendozasaurus and Futalognkosaurus, members of Lognkosauria, based on the presence of these lateral laminae on its neural spines.

A preliminary phylogenetic analysis supported this assignment, placing Quetecsaurus as a sister taxon of the clade formed by Mendozasaurus and Futalognkosaurus.