| Named By: | F. de Lapparent de Broin, N. Bardet, M. Amaghzaz & S. Meslouh in 2014 |
| Time Period: | Late Cretaceous, 70 Ma |
| Location: | Morocco |
| Size: | Unavailable |
| Diet: | Unavailable |
| Fossil(s): | Partial skull |
| Classification: | | Chordata | Reptilia | Testudines | |
Alienochelys ("strange turtle") is an extinct genus of sea turtle known from Maastrichian-aged Cretaceous phosphates in Morocco. Its name comes from the fact that unlike other sea turtles, Alienochelys' jaws are adapted for a powerful crushing pattern, as well as its unusual cranial characteristics. It is a relative of the modern leatherback turtle, as well as the extinct Archelon.