| Named By: | M. Calzavara, G. Muscio & R. Wild in 1980 |
| Time Period: | Late Triassic |
| Location: | Italy |
| Size: | Roughly about 25 centimetres long |
| Diet: | Inectivore |
| Fossil(s): | Two species recognised, most of the skeleton is known |
| Classification: | | Chordata | Reptilia | Protorosauria | Drepanosauridae | |
Megalancosaurus is a genus of extinct reptile from the Late Triassic period of Northern Italy, and one of the best known drepanosaurids. The type species is M. preonensis; a translation of the animal's scientific name would be "long armed reptile from the Preone Valley."