| Named By: | Philippe Taquet in 1976 |
| Time Period: | Early Cretaceous, 125-112 Ma |
| Location: | Africa, Niger - Echkar Formation. Specimens also known from other locations in Africa |
| Size: | 7 to 8 meters long, 67 centimetre skull |
| Diet: | Herbivore |
| Fossil(s): | 2 almost complete individuals |
| Classification: | | Chordata | Reptilia | Dinosauria | Ornithischia | Ornithopoda | Styracosterna | Hadrosauriformes | |
Ouranosaurus (meaning "brave (monitor) lizard", alternatively "sky lizard" after the primordial Greek god Ouranos) is a genus of herbivorous iguanodont dinosaur that lived during the early Cretaceous (Aptian to early Albian age) at some point between 125 and 112 million years ago, in what is now Africa. Ouranosaurus measured about 7 to 8.3 metres (23 to 27 ft) long. Two rather complete fossils were found in the Echkar (or El Rhaz) Formation, Gadoufaoua deposits, Agadez, Niger, in 1965 and 1972. The animal was named in 1976 by French paleontologist Philippe Taquet; the type species being Ouranosaurus nigeriensis.