Castle Hill is the new name for the seat of The Hills, which existed from 1962 to March 2007. Previous Members for The Hills were Max Ruddock (1962-76), Fred Caterson (1976-90) and Tony Packard (1990-93).

The suburb of Castle Hill is the heart of Sydney's booming north-west district. Best-known today for the Castle Towers shopping centre (soon to become the biggest in Australia) and the famous Castle Hill Show, it was the site of the only organised uprising by convicts in Australia's history, on March 4 1804. The site of the insurrection is now preserved as Castle Hill Heritage Park, off Banks Road. 

The major artery connecting the Hills District to Sydney is the M2 Motorway. Hillsbus operates an express bus service down the M2 to North Sydney and the City. The electorate has one railway station at Carlingford. It also has one of the highest proportions of school age children. Local schools include Castle Hill High, Castle Hill Public, Cumberland High, James Ruse Agricultural High, Murray Farm Public, Oakhill College and Samuel Gilbert Public.

Major local issues include the lack of train services on the Carlingford line, widening Showground Road in Castle Hill, the Castle Hill bypass and associated redevelopment of the Terminus Street carpark, and the promised rail link to Castle Hill and the Rouse Hill Regional Centre. The State Government's push for urban consolidation is also impacting on people living around Carlingford station and Castle Hill town centre.