"When Qantas created the Kangaroo Route to London in 1947, it took four days and nine stops," Qantas chief executive officer Alan Joyce told a news conference in Perth.
"Now it will take just 17 hours from Perth non-stop."
Flights on the 14,498 km (9,000 mile) route will begin in March 2018.
Federal Tourism Minister Steven Ciobo said Qantas would use Perth as a hub for passengers from eastern Australia going to Britain, and the service would boost employment and tourism.
Britain is Australia's third-largest source of international visitors with more than 660,000 people coming from there to Australia last year, and spending $3.7 billion (2.9 billion pounds), Ciobo said in a statement.
The Boeing 787-9 Dreamliners used on the route will carry 236 passengers, Qantas said.
(Peter Gosnell Reuters)