Qantas has announced it will begin direct flights from Sydney to London and New York from 2025.
The new routes will be the longest passenger flights in the world, and are expected to take more than 19 hours.
A Qantas test flight direct from New York to Sydney in 2019 took 19 hours and 16 minutes.
The airline has bought 12 Airbus A350-1000s to operate the routes, and says the planes "will have the range for direct flights between Australia and any city in the world".
Qantas chief executive Alan Joyce said the airline was looking for ways to make the lengthy new routes pleasant for passengers, including a "wellbeing zone" in the centre of the planes.
"The cabin is being specifically designed for maximum comfort in all classes for long-haul flying," he said.
The A350-1000 planes will seat 238 passengers, 140 of those seats will be in economy class.
NSW Premier Dominic Perrottet said the announcement was "a huge win for the state".
The airline has operated direct flights between Perth and London since 2018, however these were suspended during the pandemic due to Western Australia's tough COVID-19 border restrictions.
It is now flying between London and Darwin instead.
The airline, with Mr Joyce as a passenger, undertook the 2019 test flight to gauge the effects of long-haul travel on passengers.
Fifty passengers and crew were fitted with technology devices to test their wellbeing during the flight and were given space for exercise.
President of the Australian and International Pilots Association (AIPA), Tony Lucas, said the announcement represented a "huge moment of renewal for the aviation industry".
Mr Lucas said the long-haul flights would present a challenge both operationally and in terms of fatigue, and those issues would need to be worked through with Qantas.
"We'll submit reports and monitor flight and study times, monitor how we are feeling both in flight and after arrival in London or Sydney ... and we'll learn from those experiences," he said.
"Given that no-one's ever operated these sort of flights before, that will be a learning experience for both Qantas and us as pilots, and we expect that the Civil Aviation Safety Authority will be involved in that process as well."
Mr Joyce said the airline had initially hoped to order the new planes in 2020, but that the pandemic had delayed the purchase.
He also announced the airline's domestic fleet would be revamped with 40 new Airbus A321s and A220s .
Those planes will touch down in Australia from late 2023.
