| Named By: | Z. Dong & Z. Tang in 1984 |
| Time Period: | Middle Jurassic |
| Location: | China - Dashanpu (Lower Shaximiao) Formation |
| Size: | About 15 meters long |
| Diet: | Herbivore |
| Fossil(s): | Partial skeletons of two individuals |
| Classification: | | Chordata | Reptilia | Dinosauria | Saurischia | Sauropodomorpha | Sauropoda | Eusauropoda | Mamenchisauridae | |
Datousaurus, meaning either "Chieftain lizard" or "Big-head Lizard" (from the Malay datou "chieftain" or Chinese da tou "Big Head" and Greek sauros/sauros "lizard") was a dinosaur from the Middle Jurassic. It was a sauropod collected from the Lower Shaximiao Formation in Dashanpu, Zigong Sichuan province, China. It shared the local Middle Jurassic landscape with other sauropods Shunosaurus, Omeisaurus and Protognathosaurus, the ornithopod Xiaosaurus and the early stegosaur Huayangosaurus as well as the carnivorous Gasosaurus.