Dubreuillosaurus (meaning "Dubreuill lizard") is a genus of carnivorous dinosaur from the middle Jurassic Period. It was a megalosaurid theropod. Its fossils were found in France.
The type species, D. valesdunensis, was originally assigned to the genus Poekilopleuron as P. valesdunensis. Ronan Allain in 2005 created the new genus name Dubreuillosaurus for this species. Its length is unknown but It was estimated to be at around 9 metres (30 ft) in length, and had an unusually low and long skull, with the length of the skull being three times the height.
Not the most easily spelled (or pronounced) dinosaur, Dubreuillosaurus was only "diagnosed" in 2005 on the basis of a partial skeleton (it was originally thought to have been a species of the obscure predator Poekilopleuron). Now classified as a megalosaur, a type of largest thropod closely related to Megalosaurus , Dubreuillosaurus was characterized by its unusually long skull, which was three times as long as it was thick.