Business groups say a second Sydney airport at Badgerys Creek could create almost 30,000 jobs in western Sydney by 2050.
The NSW Business Chamber on Tuesday released an economic report into the benefits of building an airport there.
AAP reports it found an airport at Badgerys Creek could be operational by 2027 with up to 33 million passenger movements by 2050.
The report said it would create about 20,000 jobs directly and a further 10,000 in the wider community by stimulating economic activity in the region.
An airport could generate more than $A6.5 billion in output for western Sydney, the report found.
"We now have the proof that there are 28,000 jobs ready to be created," said NSW Business Chamber chief executive Stephen Cartwright.
"In some parts of Western Sydney, youth unemployment is around 30%, so a decision to proceed with a second Sydney airport at Badgerys Creek will provide a clear-cut boost to the economy of Western Sydney."