Structures indicative of progressive deformation by ductile transpression in the middle to lower crust are described from the Waller Hills area of the Mawson Escarpment, situated in the Antarctic Southern Prince Charles Mountains. Lithodemic components within the Waller Hills, including grey gneiss and supracrustals, reflect a Palaeo-Mesoproterozoic basement and cover sequence that was inverted at ~1000 Ma, synchronous with the production of high-grade transposition fabrics and folds in a presumably collisional tectonic setting. We infer that the Waller Hills represent the continuation of a Grenville-age East Antarctic orogen (the Rayner Complex) into the Southern Prince Charles Mountains. Evidence of any significant reworking at ~500 Ma is inconclusive.