Sachicasaurus is an extinct genus of brachauchenine pliosaurid known from the Barremian of the Paja Formation, Altiplano Cundiboyacense in the Colombian Eastern Ranges of the Andes.

The genus name Sachicasaurus refers to Sáchica, the location where the fossil was found, and saurus, meaning "lizard" in Latinised Greek.

Diagnostic features include a very short mandibular symphysis, reduced number of mandibular teeth (17 to 18 versus 25 to 40 in other pliosaurids), slender teeth, among other features.

With a preserved length of 9.9 metres (32 ft) (which may be missing the vertebrae from the end of the tail), the specimen is interpreted as a sub-adult individual.

[3] Sachicasaurus is one of four pliosaurids from the Paja Formation, others being Acostasaurus,[4] Stenorhynchosaurus,[5] and Monquirasaurus.