Jaxartosaurus was a genus of hadrosaur dinosaur that existed during the Late Cretaceous period. Its fossils were discovered near the Jaxartes River located in the Aral Mountains of Kazakhstan. The name "Jaxartosaurus" translates to "Jaxartes lizard," which is a reference to the Jaxartes River in Kazakhstan. Our knowledge of this dinosaur genus is quite limited. It belonged to the duck-billed dinosaur group and featured large, flat cheek teeth. It was capable of both bipedal and quadrupedal locomotion and primarily sustained itself by consuming low-lying vegetation. Estimates suggest that Jaxartosaurus stood about 4.9 meters tall and measured approximately 9 meters in length.

Although not widely recognized, Jaxartosaurus possessed a distinctive hollow, helmet-shaped crest on the top of its skull, akin to the more famous Corythosaurus. Due to this hollow crest, Jaxartosaurus has been confidently categorized within the Lambeosaurinae subgroup of hadrosaurs, known for their hollow crests. The specific purpose of Jaxartosaurus's crest remains uncertain, with prevailing theories suggesting its involvement in visual displays, potential auditory functions, thermoregulation for cooling the brain, or a combination of these functions.

The name "Jaxartosaurus" originates from the Jaxartes River, an ancient term for what is now referred to as the Syr Darya River. The species name "J. aralensis" translates to "from Aral," referencing the region in Kazakhstan. Another species, named "J. fuyunensis" by Weishampel and Horner in 1990, is currently largely regarded as synonymous with the type species.