Leppington in a Sydney. The suburb located roughly 38 kilometres south-west of Sydney's CBD. It is part of the City of Liverpool. This growing area includes a lot of recently opened, state-of-the-art facilities and is particularly popular with young families and retirees looking for a laid-back lifestyle. The Sydney suburb's age distribution is currently skewed towards an older population, with the median age of residents being 35 years, according to recent statistics from the Australian Bureau of Statistics.