Horsley Park is a suburb of Sydney in the state of New South Wales, Australia. Horsley Park is located 39 kilometres west of the Sydney central business district in the local government area of the City of Fairfield. Horsley Park is part of the Greater Western Sydney region. It is a semi-rural suburb, located 5 km west of Wetherill Park and 11 km north-west of Fairfield.

The Fairfield City Council is a local government area in the west of Sydney, in the state of New South Wales, Australia. The council was first incorporated as the "Municipal District of Smithfield and Fairfield" on 8 December 1888, and the council's name was changed to the "Municipality of Fairfield" in 1920, before being proclaimed a city in 1979. The City of Fairfield comprises an area of 102 square kilometres (39 sq mi) and as of the 2021 census had a population of 208,475. The mayor of the City of Fairfield is Cr. Frank Carbone, the first popularly-elected independent mayor of Fairfield.