A non-stop Qantas flight from Sydney to Delhi took off on Monday morning, the first time the airline has flown to the Indian city in more than 40 years.
The airline is operating three flights a week on the route and will launch four weekly flights from Melbourne to Delhi from December 22.
Qantas will use an Airbus A330 on both routes and fly, for technical reasons, via Adelaide outbound. The return legs will fly directly to Sydney and Melbourne.
The two routes have been the airline's fastest-selling since borders reopened, according to the airline, with most flights in December sold out. Qantas has not flown regularly to Delhi since 1974 and stopped its last regular India route, Brisbane to Mumbai, in 2012.
Qantas domestic and international chief executive Andrew David says demand for the flights has surpassed the airline's expectations.
"There's a huge amount of pent up demand from friends and family wanting to reunite after being separated for so long," he said. "Forward bookings for the next few months are well ahead of our initial forecasts, so while it's early days, it's an exciting start.
"The level of pent up demand on this route can be seen by the fact that almost all customers travelled as planned, despite the temporary three-day additional isolation requirement."
NSW and Victoria last week announced all international arrivals would need to isolate for 72 hours after the discovery of the Omicron variant of COVID-19. Those arriving from eight countries in southern Africa will have to enter 14 days' quarantine. Qantas currently plans to go ahead with the resumption of direct flights between Sydney and Johannesburg from January 4.
In order to enter India, travellers must provide proof of a negative PCR COVID-19 test within 72 hours of travel. Qantas also requires all passengers to provide proof of vaccination against COVID-19.
In response to the Omicron variant, India also now requires passengers who arrive from "at risk" countries to quarantine for seven days. The list of at risk countries currently includes all of Europe, along with Singapore and New Zealand, but not Australia.
Qantas is restarting a large number of international flights this month, in addition to those that have already resumed, including Sydney-Fiji (December 11), Sydney-Vancouver (December 18), Melbourne-Los Angeles (December 19) and Sydney-Honolulu (December 20).