Plagiobatrachus is an extinct genus of plagiosaurid temnospondyl.

Plagiobatrachus was described for vertebrae and partial mandibular material with pustular ornamentation for the type species, P. australis, by Anne Warren.

[1] This remains the only plagiosaurid known from Australia and one of the few records from the present-day southern hemisphere.

The vertebrae of plagiosaurids are fairly distinctive in having a single massive central element and neural arches that sit between successive centra (intercentral), allowing for the identification of the vertebral material as that of a plagiosaurid.

[2] However, the fragmentary nature of the material and the absence of any additional recovered material has limited the study of this taxon.