The news, which comes one week after the British low-cost airline revealed it had applied to Austrian authorities to establish a new Vienna-based EasyJet Europe division, was contained in a trading update.
"Our European AOC (air operator's certificate) has now been awarded and the first flight by an EasyJet Europe aircraft takes place today," said the company's outgoing chief executive Carolyn McCall.
"That means our flying rights in Europe will be secure after the UK leaves the EU."
The Luton-based airline also lifted its profits outlook for the year on rising third-quarter revenues and passenger numbers, and "strong" cost controls.
Profit before taxation is forecast to stand between £380 million and £420 million ($495-$550 million, 430-474 million euros).
The airline's previous consensus guidance, given in May, stood at £367 milllion.
"Following a rigorous and comprehensive year-long process, EasyJet is today announcing that it has been awarded an AOC by Austro Control and an airline operating licence by Austria's Federal Ministry for Transport, Innovation and Technology," the carrier said.
"These allow EasyJet to establish a new airline, EasyJet Europe, headquartered in Vienna and will enable EasyJet to continue to operate flights both across Europe and domestically within European countries after the UK has left the EU."
The airline will continue to operate those flights "regardless of the outcome of talks on a future UK-EU aviation agreement".
The announcement came at the end of a year-long "rigorous and comprehensive" process, it added.
EasyJet Europe will become the group's third airline division after EasyJet in Luton, north of London, and EasyJet Switzerland in Geneva.
Earlier this week, the company announced Monday that McCall will step down at the end of the year to become head of British commercial broadcaster ITV. A search for her successor has already begun.
Britain will leave the EU in March 2019 after voting in a referendum last year in favour of its departure.