The carrier on Friday (15 October) confirmed it will operate an up to five-times-weekly Sydney-London service starting 1 November.
London flights will operate via Darwin until at least April 2022, Qantas said.
It comes after Australia’s federal government, and the administration in New South Wales, confirmed the territory’s borders would reopen from the start of next month.
The New South Wales government has also opted to end quarantine for fully vaccinated arrivals.
Besides up to five London services a week, Qantas will also operate up to four Sydney-Los Angeles flights from the start of November.
It will deploy Boeing 787 Dreamliner aircraft on both the London and Los Angeles routes.
Initial flights to both London and Los Angeles will be limited to Australian citizens, permanent residents and their immediate families and parents.
From 18 December, it will restart flights to Singapore, Fiji and Vancouver, with Qantas vowing to add more destinations in the new year.
However, it said owing to the developments in New South Wales, it could yet bring forward some additional routes to and from Sydney "if possible".
“Bringing forward the reopening of Australia to the world and removing quarantine requirements for fully vaccinated travellers entering New South Wales is a massive step towards life as we knew it," said Qantas Group chief executive Alan Joyce.
“In just a little over two weeks, Australians around the world can fly into Sydney and people from around Australia can leave on trips they’ve been waiting almost two years to take. We hope other states will do the same once they reach the 80% [vaccination] target."
Joyce, though, despite hailing the move a "fantastic start" for a resumption of international travel, said it would be "a long time" before the landscape returns to any kind of normality. “Removing quarantine for the fully vaccinated is a sensible approach and brings New South Wales into line with many other global cities," he added.