Ryanair says it carried more than six million passengers last month - an increase of 20%.
The carrier says its annual traffic to December rose 6% to 86.4 million customers.
While its load factor - the percentage of seats filled on its flights - increased 7% points to 88%.
Ryanair's share price has soared this morning on the back of the increased passenger numbers.
The Irish airline has recently launched a new website, appealing to travelers from the US. The site allows customers to browse and pay for flights in US dollars.
The introduction of transatlantic flights have been a long stated ambition of the company - but that remains at least three years away.
Ryanair CEO Michael O'Leary has publicly said that he would like the company to introduce a low-cost service between the US and Europe.
He thinks that Ryanair could fly between some 15 European cities and 12 US destinations.
But he has cited the difficulty of sourcing long-haul aircrafts as one issues that is slowing down the project.
Newstalk.com's business editor Ian Guider says it has been a good year for Mr O'Leary's airline.
