Qantas, which has been working on the no-stopover flights under Project Sunrise for a number of years, is ordering 12 Airbus A350-1000s wide-body aircraft to service the routes.
"It's the last frontier and the final fix for the tyranny of distance that has traditionally challenged travel to Australia," CEO Alan Joyce said in a statement on Monday.
"The cabin is being specifically designed for maximum comfort in all classes for long-haul flying."
The new planes are 25 per cent more fuel efficient than previous generation aircraft and will carry 238 passengers in four classes, including first, business, premium economy and economy, and have a "wellbeing zone" in the centre.
Passengers can use the wellbeing area for stretching exercises and take advantage of a self-service station to boost hydration.
The first flight is due to take off from Sydney by the end of 2025 and comes after three research flights from New York and London to Sydney in 2019.
Federal minister Stuart Robert said it was a great vote of confidence in the Australian economy.
"It's superb," he told Nine Network. "It demonstrates that Australians want to get out and travel again."
Before the coronavirus pandemic erupted, the so-called Kangaroo route between Australia and the UK was one of Qantas' busiest international operations.
NSW Premier Dominic Perrottet said the fact Qantas was putting Sydney at the heart of its plans cemented the state capital's status as Australia's only global city.
"This ... will help create 2500 jobs and generate more than $300 million in local economic benefits," he said.
Qantas began operating non-stop 17-hour flights from Perth to London in 2017.
The airline also announced it is renewing its domestic narrow-body fleet from late 2023, with an order of 20 Airbus A321XLRs and 20 A220s under Project Winton, as the airline's Boeing 737s and 717s are retired.
Meanwhile, the carrier released its third-quarter trading update on Monday, showing domestic travel demand is returning to pre-COVID-19 levels ahead of expectations.
Demand for international travel is also recovering well, albeit at a slower pace due to some markets remaining closed or heavily restricted.
But bookings for destinations including London, Los Angeles, South Africa and Bali are all above pre-coronavirus levels.
Qantas maintained its forecast for underlying earnings of between $450 million to $550 million in the second half of fiscal 2022.
