| Named By: | J. Lu, S. Li, G. Wang, J. Zhang & Z. Dong in 2006 |
| Time Period: | Middle Jurassic |
| Location: | China, Yunnan Province - Zhanghe Formation |
| Size: | About 17 meters long |
| Diet: | Herbivore |
| Fossil(s): | Partial post cranial remains |
| Classification: | | Chordata | Reptilia | Dinosauria | Sauropoda | Eusauropoda | Mamenchisauridae | |
Yuanmousaurus ("Yuanmou lizard") was a sauropod dinosaur from the Middle Jurassic period of China. It is known from incomplete remains, recovered in 2000 from the Zhanghe Formation in Yuanmou County in Yunnan Province. Yuanmousaurus was a relatively large sauropod and may have reached about 17 meters (56 ft) in length. It was a basal member of the Sauropoda, but its exact systematic position is unclear. A recent study placed Yuanmousaurus within the family Mamenchisauridae. The only and type species was Yuanmousaurus jiangyiensis.