Quaesitosaurus (kwee-siet-oh-sore-us) is a Cretaceous titanosaurian sauropod (the last of this order) found by Kurzanov and Bannikov in 1983. The type species is Quaesitosaurus orientalis. Quaesitosaurus grew to 23 metres long. It lived from 80 to 65 million years ago.

Quaesitosaurus was a herbivorous dinosaur that was active during the Santonian-Campanian ages of the Upper Cretaceous period 86-84 million years ago.