Vueling is to fill the void left by the collapse of Spanish rival Spanair by raising summer capacity by a quarter.
The carrier is to hike capacity from its base in Barcelona by 50% and 25% overall.
Vueling is to add a total of 33 new frequencies to its existing domestic and European routes.
This will see up to 14 daily flights between Barcelona and Madrid, nine to Bilbao and eight to Seville and Palma.
New routes from Barcelona to Copenhagen and Stockholm four times a week have been brought forward from their original start date of March 25.
Vueling will also operate former Spanair routes to Berlin and Hamburg and increase frequency on its existing Munich service from Barcelona.
New routes from Bilbao will run to the Canary Islands with flights to Tenerife three times a week, Las Palmas twice a week and Lanzarote twice a week.
The airline is in “advanced talks” with lessors to add five or more Airbus A320 aircraft to its current fleet of 43 to cope with the sudden rise in capacity.
CEO Alex Cruz said that Vueling has “more positive attributes than any player” to offer an “unbeatable product within Spain and throughout Europe.”
Cruz cited a high number of multi-frequency routes, availability on all GDS systems, online check-in, seat assignment and business class service elements such as two-per-row seating, guaranteed cabin-luggage space, Oneworld-aligned miles “and many other characteristics that set us apart from the low-cost model”.