Sydney, New South Wales
|Population||3,135 (2016 census)|
|Location||37 km (23 mi) south-west of Sydney CBD|
|LGA(s)||City of Liverpool|
Sadleir is a suburb in south-western Sydney, in the state of New South Wales, Australia. Sadleir is located 37 kilometres south-west of the Sydney central business district, in the local government area of the City of Liverpool.
According to the 2016 census, Sadleir had a population of 3,135. The average age was 33, slightly lower than the national average, with higher than expected numbers of people in the 0-14 and 65 plus age groups. There was a significant housing commission population with around a third of the suburb's dwellings belonging to the Department of Housing. The median household income of $861 per week was substantially less than the national average ($1438). In Sadleir 56.3% of people were born in Australia, with the most common countries of birth were Vietnam 7.2%, Lebanon 6.3%, Iraq 3.8%, New Zealand 1.9% and Fiji 1.5%. 
- Australian Bureau of Statistics (27 June 2017). "Sadleir (State Suburb)". 2016 Census QuickStats. Retrieved 12 April 2018.
- The Book of Sydney Suburbs, Compiled by Frances Pollon, Angus & Robertson Publishers, 1990, Published in Australia ISBN 0-207-14495-8, page 236
- "Sadleir Public School". NSW Department of Education. Retrieved 7 July 2008.