Pemulwuy is a suburb in Greater Western Sydney, in the state of New South Wales, Australia. Pemulwuy is located 30 kilometres west of the Sydney central business district in the local government area of the Cumberland Council. Pemulwuy is home to the highest point between the Blue Mountains and Sydney, the summit of Prospect Hill.

Greater Western Sydney (GWS) is a large region of the metropolitan area of Greater Sydney, New South Wales (NSW), Australia that generally embraces the north-west, south-west, central-west, far western and the Blue Mountains sub-regions within Sydney's metropolitan area and encompasses 11 local government areas: Blacktown, Blue Mountains, Camden, Campbelltown, Cumberland, Fairfield, Hawkesbury, Liverpool, Parramatta, Penrith and Wollondilly. It includes Western Sydney, which has a number of different definitions, although the one consistently used is the region composed of ten local government authorities, most of which are members of the Western Sydney Regional Organisation of Councils (WSROC). The NSW Government's Office of Western Sydney calls the region "Greater Western Sydney".