More than 10.5 million passengers passed through the main Irish airports in the third quarter of this year, the latest figures from the Central Statistics show.
This marked an increase of 5.4% over the same time last year.
The CSO figures show that passenger numbers increased in the three months from July to September in Cork and Dublin airports.
But they fell in Shannon, Knock and Kerry, when compared with the same three months last year.
Dublin Airport accounted for 84.5% of all air passengers carried in the third quarter of 2017.
The CSO said that in the nine months to September, a total of 26.6 million passengers travelled through the main Irish airports, up 5.3% on the same time last year.
Today's figures show that a total of 73,364 flights were handled by Ireland's main airports in the third quarter of 2017, with Dublin accounting for 82.5% of all flights.
London-Heathrow, London-Gatwick and Amsterdam-Schiphol were the most popular routes for passengers for Dublin airport in the third quarter of the year.
For Cork airport, the top three routes were London-Heathrow, London-Stansted and Faro.
Meanwhile, the biggest route for Shannon was London-Heathrow, the top route for Knock was London-Stansted and the top route for Kerry was London-Luton.
Today's CSO figures also reveal that the country's main airports handled a total of 39,582 tonnes of freight in the third quarter of 2017, 93.6% of which was international freight.