The airline bmibaby has announced seven new routes from George Best Belfast City Airport.
Flights to Malaga, Alicante, Palma, Faro and Ibiza will run from March 2012, and go on sale on Wednesday.
A year-round service to Amsterdam will also operate from October 2011, along with winter flights to Geneva for 2011.
It comes as the airline announced it was pulling out of Cardiff and Manchester after the summer season.
Bmi said two new additional aircraft will be based in Belfast to service the increased number of flights.
Julian Carr, Managing Director, bmibaby, said the airline was "committed" to flying from Northern Ireland.
"Bmibaby will be the only low-cost airline to operate the new routes directly from Belfast City Airport, and this will make getting away for a sunshine, ski or city break more accessible from Northern Ireland," he said.
"The new routes build on our recent launch of the Belfast city to Stansted service, and the relocation from Belfast International Airport to Belfast City Airport."
Mr Carr said the new European flights would complement their existing services at the George Best Belfast City Airport.
However, some local residents have voiced opposition to the move.
The chair of the Belfast City Airport Watch Steering Group, Liz Fawcett, said residents are angry that politicians are allowing the City Airport to be turned into an international airport.
"It's completely inappropriate for an airport on the doorstep of major residential areas to be permitted to become an international airport when we already have an international airport on a virtual greenfield site just up the road," she said.
"This move has been made in the absence of any robust and properly enforced noise controls."
Belfast City Airport Watch estimates that more than 40,000 residents in east and south Belfast, and north Down are affected by aircraft noise linked to the City Airport
Brian Ambrose, chief executive of George Best Belfast City Airport, said it was the "most significant" announcement in the airport's recent history.
"Direct European routes have long been an ambition of this airport and we believe strongly that our growing customer base throughout Northern Ireland will avail of the bmibaby services."
The changes mean 69 jobs are at risk in Cardiff, but the airline says it hopes to redeploy all of these to Belfast, Birmingham and East Midlands.
Almost 100 jobs are at risk in Manchester, with the airline hoping to redeploy 64 of those.