Passengers travelling to the Gold Coast will be the first to take off from Australia’s youngest airport.

Western Sydney International (Nancy-Bird Walton) Airport will open to commercial passengers on Sunday after almost seven years of construction and eight decades of planning.

Many leaders have long believed Australia’s most populous city deserved a round-the-clock, second airport for both cargo and passengers.

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Simon Hickey, chief executive of WSA Co Limited — established by the federal government to develop and operate the new facility — is confident the airport will deliver on the brief.

“WSI is the most transformational piece of infrastructure our nation has seen since the Sydney Harbour Bridge,” he told AAP.

“It brings the world closer to western Sydney and opportunity closer to home, creating new meaningful jobs for generations to come.

“Young people growing up in the west can now look to the sky and see their future is bright and right here, in their own backyard.”

Construction on the airport began in 2018 after the Abbott government formally signed off on the Badgerys Creek site in 2014.

The capacious Nancy-Bird Walton terminal - named for the pioneering Australian aviator - was designed through a selective competition.

Earth workers moved more than 25 million cubic metres of soil and rock to prepare the site before builders delivered the project on time and on budget in 2025.

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Local governance leaders and western Sydney businesses now hope the airport will transform the region into an economic powerhouse.

Liverpool City Council Mayor Ned Mannoun said greater Sydney’s future was “only limited by imagination”.

His Penrith counterpart Todd Carney agreed but said state and federal governments would have to support growth with turbo-charged investment in roads, amenities and critical infrastructure.

“There’s so much more potential in it if we actually just deliver on the underlying infrastructure that’s actually required,” Mr Carney told AAP.

Those in private business said many were ready to jump on opportunities, but were also waiting for those critical connections.

Former MP and Business Western Sydney leader David Borger told AAP growth would depend on connectivity.

Property Council Western Sydney regional director Ross Grove similarly said any economic dividend from the airport would require continued investment.

“As that first plane takes off today, our focus should turn to what takes off next: the jobs, investment and development this airport was built to unlock,” Mr Grove said.

The multi-billion-dollar airport is modular, with space to expand to four terminals and add a second runway.

Mr Hickey said the airport would continue to grow with the city.

“WSI is here to grow with Sydney for the coming century, expand choice for travellers and airlines, and connect more people with more places and opportunities,” he said.

Leaders hope Badgerys Creek will scale up to handle more than 80 million passengers annually by the 2060s.

Paul Fletcher, who served as federal infrastructure minister through much of the 2010s, said Australians would have to watch the master plan “play out over coming decades”.

“This is a 10, 20, 30, 50, 100-year project,” he told AAP.

So far, seven passenger carriers have committed to servicing the new airport, with Jetstar the first to ferry passengers to and from Badgerys Creek.

Bus services are moving passengers between the airport and St Marys.

A rapid-transit line is expected to open along the route in 2027.