Werrington is a suburb of Sydney, in the state of New South Wales, Australia. It is 49.3 kilometres (30.6 mi) west of the Sydney central business district, in the local government area of the City of Penrith and is part of the Greater Western Sydney region.

The City of Penrith is a local government area in the state of New South Wales, Australia. The seat of the city is located in Penrith, located about 50 kilometres (31 mi) west of Sydney's central business district. It occupies part of the traditional lands of the Darug people. First incorporated as a municipality on 12 May 1871, on 1 January 1949, the municipalities of Penrith, St Marys and Castlereagh and part of the Nepean Shire amalgamated to form a new Municipality of Penrith. Penrith was declared a City on 21 October 1959, and expanded westwards to include Emu Plains and Emu Heights, formerly part of the City of Blue Mountains, on 25 October 1963. As of the 2021 census the City of Penrith had an estimated population of 217,664.