Dublin Airport says more than 2.2 million passengers used it in April, a 10% increase on the same period last year.
Passenger volumes to and from continental Europe also increased by 9%, with over 1.1 million passengers travelling this route sector last month.
UK traffic increased by 11% as almost 812,000 passengers travelled to and from Britain.
Transatlantic passenger volumes also grew by 19% - with some 196,000 passengers travelling to and from North America.
Other international traffic - mainly to the Middle East - declined by 6%, as almost 58,000 passengers travelled to and from these destinations.
However domestic traffic rose by 16% to over 7,500 passengers.
The number of passengers using Dublin Airport as a hub to connect to another destinations increased by 31% - at almost 66,000 passengers.
While almost 7.8 million passengers travelled through the airport in the first four months of this year, a 15% increase over the same period last year.
Dublin Airport has welcomed over one million additional passengers so far this year.