Doonside is a suburb in the metropolis of Sydney, in the state of New South Wales, Australia. Doonside is located 40 kilometres west of the Sydney central business district, in the local government area of the City of Blacktown and is part of the Greater Western Sydney region. Featherdale Wildlife Park and the Nurragingy Nature Reserve are popular local tourist attractions.

Blacktown City Council is a local government area in Western Sydney, situated on the Cumberland Plain, approximately 35 kilometres (22 mi) west of the Sydney central business district, in the state of New South Wales, Australia. Established in 1906 as the Blacktown Shire and becoming the Municipality of Blacktown in 1961 before gaining city status in 1979, the City occupies an area of 246.9 square kilometres (95.3 sq mi) and has a population of 410,419, making it the most populous local government area in Sydney.