The Parramatta Sand Body (PSB) in Parramatta, New South Wales, Australia is an ancient sedimentary sand deposit bordering parts of the Parramatta River which today flows into Sydney Harbour. Whilst the lower portions of the sand deposit pre-date human occupation, some locations with near surface sand deposits contain dense Aboriginal archaeological sites with a profusion of stone tools and remains of hearths. We explored the timing of human occupation in Parramatta by applying optically stimulated luminescence (OSL) ages to archaeological evidence from site AT14. Interpretation of the OSL data was guided by particle size analysis and the resulting age estimates agreed with the radiocarbon dating of charcoal sampled from archaeological deposits at AT14, to provide a secure age for human occupation evidence in the Sydney region at 31 ± 2 ka. Results link the single grain overdispersion found in quartz OSL samples to trampling actions resultant of Aboriginal occupation and forms a future consideration for the effective dating of archaeological sites.