Simolestes (meaning "snub-nosed thief") is an extinct pliosaurid genus that lived in the Middle to Late Jurassic.

[2] The type specimen, NHMUK PV R 3319 is an almost complete but crushed skeleton diagnostic to Simolestes vorax, dating back to the Callovian of the Oxford Clay formation, England.

The largest specimens of S. vorax reached approximately 4.6 metres (15 ft) in length, if a head to body ratio similar to Liopleurodon is applied.

It is possible Simolestes was also ecologically separated from other contemporary pliosaur genera such as Liopleurodon and Pachycostasaurus by hunting in deeper waters or at night, as modern cephalopods exhibit diurnal feeding cycles, spending daylight in deeper, safer waters, and rising at night to feed.

[8] Anningasaura "Plesiosaurus" macrocephalus Archaeonectrus Macroplata Atychodracon Eurycleidus Rhomaleosaurus Meyerasaurus Maresaurus Thalassiodracon Hauffiosaurus Attenborosaurus