Nanyangosaurus is a genus of herbivorous ornithischian dinosaur belonging to Hadrosauroidea that lived in the Late Cretaceous of present-day Henan Province, China.

The type species, Nanyangosaurus zhugeii, was described by Xu Xing, Zhao Xijin, Lü Junchang, Huang Wanbo, Li Zhanyang and Dong Zhiming in 2000.

The specific name honours one of the most famous historic inhabitants of that city, the legendary strategist Zhuge Liang.

The first digit of the hand was completely absent including the first metacarpal; according to the describers this was not an accident of preservation but the actual condition of the living animal.

According to a cladistic analysis performed by the describers, Nanyangosaurus was a basal member of the Iguanodontia, more derived than Probactrosaurus and closely related to the Hadrosauroidea.