Agnosphitys ("unknown begetter"; sometimes mistakenly called Agnostiphys or Agnosphytis) is a disputed genus of dinosaur. It contains only one species, the type species A. cromhallensis. Its remains include an ilium, maxilla, astragalus and humerus, which date variously from the Norian and Rhaetian stages of the Late Triassic. It may be a chimera.
Agnosphitys lies close to the ancestry of dinosaurs, although exactly where is disputed by researchers. Some consider it a saurischian dinosaur close to the beginnings of dinosaur evolution, while others consider it a dinosauromorph, an archosaur near the evolution of the dinosaurs.
The type species, Agnosphitys cromhallensis, was described by Fraser, Padian, Walkden and Davis in 2002. The fossils, consisting of a partial skeleton including referred material, were found in Avon, England.