The name Leppington comes from the property granted to William Cordeaux in 1821. Leppington Park House was a huge two storey home with its own private ballroom built by convict labour. It was destroyed by fire in the 1940s. The bricks at the base of the outdoor stage at Leppington School came from this building.
In 1914 an area of Leppington was subdivided as the Raby Estate, named after the property Raby some 3269 acres granted to Alexander Riley in 1810. The 1914. The subdivision was developed by Arthur Rickard & Co. People interested in buying a lot would be met by a sulky either at Ingleburn or at the Coach crossing at the Water Canal Bringelly Road. Rickard Road in the estate was named after the developer.
The school on the estate was opened as Raby School in 1923. The first teacher was Mr Cox and he taught about 40 pupils between the ages of 6 and 15. It remained a one-teacher school until 1951. In 1955 the name was changed to Leppington Public School. The Post office, also on the Raby Estate was established in 1930 and remained on its original site until 1981. The Riley estate south of the Raby Estate was subdivided in 1956.The area has supported small farms and vegetable and flower market gardens. The area is subject to planned development as part of South West Sydney Growth Area. A corridor of land is being resumed by NSW State Government for an extension to the Liverpool rail line with a station in the north-eastern part of Leppington due to open by 2014.