Greater Western Sydney, encompassing the areas of Parramatta, Bankstown, Liverpool, Penrith, and Fairfield, is often dubbed Sydney's "second CBD." Parramatta stands out as the region's commercial hub, ranking as the sixth-largest business district in Australia. Established in the same year as the harbor-side colony, Parramatta is a key player in the economic landscape of Greater Western Sydney, which covers an expansive area of 5,800 km² (2,200 sq mi) and supports a population of approximately 2.3 million as of 2017.

This region is notable for its rich multicultural tapestry. Suburbs like Cabramatta have earned the nickname "Little Saigon" due to their significant Vietnamese community, while Fairfield has been affectionately dubbed "Little Assyria," reflecting its large Assyrian population. Harris Park is renowned as "Little India," showcasing its diverse Indian and Hindu communities. The area's demographic is predominantly working-class, with a strong employment base in heavy industries and vocational trades.

Among the attractions in Greater Western Sydney is Raging Waters, a popular water park located in the suburb of Prospect within the City of Blacktown. The Auburn Botanic Gardens draw thousands of visitors annually, including many from overseas. The region is also home to Sydney Olympic Park, originally developed for the 2000 Summer Olympics, and Sydney Motorsport Park, a well-known circuit in Eastern Creek. Furthermore, Prospect Hill, a historically significant ridge, is the only location in Sydney known for ancient volcanic activity and is listed on the State Heritage Register.

Wildlife enthusiasts can visit Featherdale Wildlife Park in Doonside, a major tourist attraction, or explore Sydney Zoo, which opened its doors in 2019 in Bungaribee. Old Government House in Parramatta, established in 1799, is Australia's oldest surviving public building and has gained recognition by being included in both the Australian National Heritage List and the World Heritage List as part of the Australian Convict Sites.

In the southwestern region of Macarthur, the city of Campbelltown serves as a significant population center, especially until the 1990s when it was considered separate from Sydney. The Macarthur Square shopping complex in Campbelltown is one of the largest in Sydney. The southwest is also home to the Bankstown Reservoir, the oldest elevated reservoir made of reinforced concrete still in operation, and the Bland Oak, one of Sydney's oldest trees, planted in the 1840s.

Overall, Greater Western Sydney presents a vibrant mix of economic activity, cultural diversity, and historical significance, making it an integral part of the greater Sydney region.