Stanhope Gardens is located 39 kilometres north-west of the Sydney central business district in the local government area of City of Blacktown. Stanhope Gardens is part of Greater Western Sydney and is considered to be part of the Hills District.
John Hillas (1768–1837) arrived in Australia in 1801 and received two land grants (in 1801 and 1804) on the Windsor Road. The second of these, of 150 acres, he named "Stanhope Farm". He established an inn, the "Stanhope Arms" on Windsor Road to cater for the traffic between the Macquarie Towns and Parramatta.
By 1856 the Pearce family owned "Stanhope Farm". In 1928 Jack Peel bought "Stanhope Farm" and called it "Stanhope Park Dairy".
In 1973 the New South Wales Housing Commission compulsorily resumed Stanhope Park Dairy.
The suburb name reflects these early properties. Stanhope Gardens Estate opened in 1995 and was formally recognised as a suburb in 1996.
When Stanhope Gardens was first being developed into what it is today, it was called "Irish Town", Kellyville and Parklea. A petition was sent around with most people voting to keep Stanhope in the name, becoming Stanhope Gardens.
Stanhope Village is a sub-regional shopping centre anchored by a Coles supermarket, Liquorland and Kmart, plus 100 other specialised retail, service, fashion and food outlets.
Public transport is provided by private bus operators Hillsbus and Busways, going to the Sydney CBD, Parramatta, Rouse Hill, Blacktown, Macquarie Park and Castle Hill.
The suburb is serviced by Riley station on the Rouse Hill- Parramatta T-way, and the Stanhope station on the Blacktown- Parklea T-way.
New housing developments are currently underway in the area. This is mainly on the Newbury estate which includes exclusive clubhouse facilities each with tennis, swimming and shared barbecue facilities for use by surrounding residents. Newbury is Community Association based Torrens Titled property, which means that the residents hold full title to their own property but financially contribute to the running costs and Community Association facilities of the Estate. Land in this estate has also been reserved for future government primary and secondary schools. Also located within Stanhope Gardens is the Parklea Garden Village/Sydney Gateway Holiday Park Mobile Home Village.