Abstract The hominin pelvis is a remarkable structure that plays a central role in many critical biological processes, most notably bipedal locomotion and parturition. Here we describe each pelvic element from Sterkfontein and reconstruct the pelvis of the partial skeletons of Sts 14 and StW 431. Based on preserved contours, if human sexing methods can be accurately applied to australopiths, it is likely that Sts 14 represents a female individual, with the larger size, narrower greater sciatic notch of Sts 65 and StW 431 and other morphologies suggesting that these individuals were male. Some degenerative defects of the StW 431 acetabulum also suggest this may have been an older adult. This chapter also presents complete pelvic reconstructions of all of these fragmentary hipbone fossils.