Histriasaurus (HIS-tree-ah-SAWR-us) (meaning "Istria lizard") was a genus of dinosaur from the Early Cretaceous (Hauterivian to Barremian stages, around 135-125 million years ago).

The holotype, specimen WN V-6, was found in a bonebed in lacustrine limestone exposed on the seafloor off the coast of the town of Bale on the Istrian peninsula in Croatia by Dario Boscarolli during the 1980s, and described in 1998 by Dalla Vecchia.

[1] The specific name honours the discoverer of the site, Darío Boscarolli.

Although some authors consider Histriasaurus a dubious taxon, more recent papers support the original classification.

Phylogenetic analyses published in 2007 and 2011 placed Histriasaurus as the most basal member of Rebbachisauridae.