| Named By: | Thomas Henry Huxley in 1877 |
| Time Period: | Late Triassic Carnian |
| Location: | Scotland |
| Size: | 4 meters long |
| Diet: | Carnivore |
| Fossil(s): | At least three specimens |
| Classification: | | Chordata | Reptilia | Archosauria | Crurotarsi | Pseudosuchia | Ornithosuchidae | |
| Also known as: | | Dasygnathus longidens | Ornithosuchus taylori | Ornithosuchus woodwardi | |
Ornithosuchus (meaning "bird crocodile") is an extinct genus of pseudosuchians from the Late Triassic (Carnian) Lossiemouth Sandstone of Scotland. It was originally thought to be the ancestor to the carnosaurian dinosaurs (such as Allosaurus). However, it is now known to be more closely related to crocodilians than to dinosaurs.
Despite this relationship to crocodiles, Ornithosuchus was able to walk on its hind legs, like many dinosaurs. However, it probably spent most of its time on all fours, only moving bipedally when it needed to run rapidly. Its skull also resembled those of theropod dinosaurs, but more primitive features included the presence of five toes on each foot and a double row of armoured plates along the animal's back. Ornithosuchus was around 4 metres (13 ft) in length.