The city to be developed on the doorstep of Sydney's second airport at Badgery's Creek will be named Bradfield in honour of the engineer who helped shape Sydney.

Dubbed a new "hi-tech" city, the area spans more than 100ha and sits north of the existing suburb of Bringelly in western Sydney.

NSW Premier Gladys Berejiklian said on Tuesday that Bradfield would grow to become Sydney’s third city.

“When the greater commission of Sydney came to us with a proposal to have three main cities within greater Sydney, of Sydney, Parramatta, and now this third city, it was just a vision, and now it’s becoming reality,” Berejiklian said.

“What are paddocks now will be a thriving, bustling city centre.

“We want Bradfield to be as iconic as the existing major city centres of Sydney and Parramatta.”

Until this week referred to as the "Aerotropolis core", the new city centre will be built near the Western Sydney International Airport, and become home to manufacturing, research, science and education.

Bradfield’s ‘city-shaping’ impact

John Bradfield was a renowned engineer who designed and oversaw the construction of the Sydney Harbour Bridge and Sydney’s original railway network.

The name Bradfield was selected after community consultation and a "name the place" process, with a panel settling on the final decision to honour Bradfield’s city-shaping impact on Sydney.

John Bradfield’s grandson Jim Bradfield was at Tuesday's announcement.

“It is a great honour that my grandfather’s name continues to be associated with major infrastructure developments in and around Sydney,” Bradfield said.

“We hope his achievements will inspire generations to come and help shape the future of our urban landscape.”

The name Bradfield will now be put to the Geographical Names Board of NSW.

The state government said it has 18 foundation partner commitments, including with Suez, Siemens, Hitachi, Sydney Water and Northrup Grumman, and is still formalising relationships with partners FedEx, Romar Engineering and Quickstep.

Berejiklian said the city will be a driver of economic growth and generate up to 200,000 jobs in western Sydney.