| Named By: | Friedrich von Huene in 1932 |
| Time Period: | Early Cretaceous |
| Location: | Australia, New South Wales, Lightning Ridge - Griman Creek Formation |
| Size: | Unknown due to lack of remains, but very roughly estimated at somewhere between 1 and 1.5 meters long |
| Diet: | Herbivore |
| Fossil(s): | Partial end of a femur that has been turned to opal |
| Classification: | | Chordata | Reptilia | Dinosauria | Ornithischia | Ornithopoda | Hypsilophodontidae | |
Fulgurotherium (meaning "Lightning Beast") is the name given to a genus of dinosaur from the Early Cretaceous (Albian). It lived in what is now Australia.
The type species, Fulgurotherium australe, was named by Friedrich von Huene in 1932. The genus name is derived from Latin fulgur, "lightning", and Greek therion, "beast", a reference to the Lightning Ridge site in New South Wales. The specific name means "southern" in Latin. The holotype is BMNH R.3719, the opalised lower end of a femur, indicating a total body length of 1 to 1.5 metres.
Von Huene thought it was a theropod, a member of the Ornithomimidae. It has later been described as a hypsilophodont, a primitive ornithopod. However, this was based on a contentious reference of bones found in the Dinosaur Cave, leading to a possible confusion between multiple species of Euornithopoda. Most researchers today consider it a nomen dubium.
Its name is an unusual example of a name in which -therium was used for an animal which is not an extinct mammal.