Wizz Air saw the percentage of carryings outpace increased capacity in December.
Passenger numbers rose last month by 22% to more than 1.5 million.
The result was achieved as capacity rose by 21% to almost 1.8 million seats over the same month in 2014. The load factor increased marginally to 85.1%.
The eastern and central European budget carrier expanded its fleet to 65 aircraft last month with the introduction of a second new generation Airbus A320neo at its base in Budapest.
The airline announced 11 new routes in December from four countries – Romania, Macedonia, Poland and Lithuania.