Wetherill Park is a suburb in Greater Western Sydney, in the state of New South Wales, Australia.

Wetherill Park is located 34 kilometres west of the Sydney central business district, in the local government area of the City of Fairfield.

With the commencement of the Prospect Reservoir Waterworks, a local storekeeper, Samuel Booth, made available a section of his land for a school, free of charge.

Wetherill Park is home to the largest industrial estate in the Southern Hemisphere, with companies such as Jaguar, BMW, Subaru and Mercedes-Benz situated in the area.

Despite the heavy industrial presence, the suburb maintains a coppice environment dominated by eucalyptus trees.

[8] Transitway bus route T80 operated by Transit Systems Sydney, opened in 2003 and runs partly through Wetherill Park.

Wetherill Park has a humid subtropical climate (Cfa) with warm to hot summers and cool, drier winters.

^[note a] : The closest weather station is located within Prospect Reservoir on the Prospect–Wetherill Park border (in the northern outskirts of the suburb).

According to the 2021 Census, the most common ancestries in Wetherill Park were Australian 11.0%, Assyrian 10.7%, Italian 9.4%, English 8.7%, and Iraqi 7.4%.