Leonerasaurus is a new genus of herbivorous prosauropod dinosaur. It was described in 2011 by Diego Pol, Alberto Garrido, and Ignacio A. Cerda. The type specimen, which is an incomplete subadult, was found in the Las Leoneras Formation of Argentina. This formation is probably Early Jurassic (Hettangian) in age.
The type species is L. taquetrensis. Leonerasaurus is related to the contemporary genera Anchisaurus and Aardonyx.
The type specimen of Leonerasaurus consisted of parts of dentary and some teeth, neck and trunk vertebrae, a sacrum, parts of the pectoral (shoulder) and pelvis (hip) girdle, as well as several limb bones. Leonerasaurus means "Las Leoneras lizard", after the place it was found.