Fossil remains for Paranthropus robustus have been found in South Africa, and indicate P. robustus was similar to Australopithecus africanus in many ways with the exception of an extremely robust masticatory apparatus. Like australopithecines, P. robustus exhibits a high degree of sexual dimorphism, molarized premolars, and lower limb adaptations for bipedalism. Fossil evidence for bipedalism includes a partial foot specimen.

P. robustus differs from australopith with a larger absolute brain size (530 cc), a pronounced sagittal crest, very large flattened face, a brow ridge separated by a slight sulcus, relatively smaller incisors, large mandible, and very large cheek teeth.

P. robustus hand morphology suggests a grip capable of tool use.

The type specimen for P. robustus is TM 1517 which was found at Kromdraai and dates to 2 million years ago.