The new route complements Air New Zealand’s existing services into Sydney Kingsford Smith Airport.
Major construction on the new A$5.3 billion ($5.7b) WSI is now complete, ABC News reported.
WSI chief executive Simon Hickey said the new airport was Sydney’s only 24-hour airport.
“This new strategic partnership, supported by the Western Sydney International Take-off Fund, will connect one of Australia’s most diverse and fastest growing regions – Western Sydney – with New Zealand’s largest city and main holiday gateway,” he said.
“WSI’s innovative terminal facilities and use of next-generation technology will offer Air New Zealand passengers a seamless, intuitive and meaningful airport experience, while our 24-hour capacity will give people more choice on when and how they choose to fly. We can’t wait to welcome you.”
Steve Kamper, Minister for Jobs and Tourism with the Australian Labor Party, said he expected the new route to be popular.
“Sydney is the top overseas city of choice for Kiwis, and this new direct connection to Western Sydney will unlock incredible opportunities for local tourism, business and jobs,” he said.
“The economics are very simple, if we want to grow our visitor economy, we need more visitors.”
Last week, Air New Zealand announced it would operate a Christchurch to Adelaide service.
The service to Adelaide will start on October 27, with about 15,000 seats available until late March.