Proceratosaurus was a genus of basal tyrannosauroid from the Bathonia Stage (Middle Jurassic). Discovered in Gloucestershire, England, the holotype smecimen is known from one skull. Since the top of the skull was missing, part of what is now believed to have been an extensive crest was believed to be a nasal horn, similar to Ceratosaurus. Proceratosaurus was then believed to have been an ancestor of Ceratosaurus. However, scientists though it may be a coelosaur, only distantly related to Ceratosaurus. Grouping it with Ornitholestes was also suggested, again because of the nasal crest. However, this was disproved in Ornitholestes. A basal Allosauroid was also suggested as a candidate for its classification.
After a major re-evaluation, Proceratosaurus was grouped along with Guanlong, Sinotyrannus and Kileskus in a family of basal tyrannosaurids known as Proceratosauridae. Proceratosaurus was likely covered with small proto-feathers, like other basal tyrannosaurs.