Kimmerosaurus ("lizard from Kimmeridge") is an extinct genus of plesiosaur from the family Cryptoclididae.

In fact, nothing has been found to show what Kimmerosaurus may have looked like below the neck, although the atlas and the axis are similar to those of the plesiosaur Colymbosaurus.

[2][3] The first part of the genus name of Kimmerosaurus comes from the location of the first Kimmerosaurus fossils, Kimmeridge Clay deposits of Dorset, England (these deposits are also the root word for the Kimmeridgian stage of the Jurassic period).

The second part comes from the Greek word σαυρος (sauros), "lizard".

This animal may have ranged through much of what is now the Jurassic Coast, a World Heritage Site in the southern United Kingdom.