Of all the passengers handled in the third quarter, Dublin airport accounted for 85 percent of the total, followed by Cork airport (7 percent) and Shannon airport (5 percent) with the remaining to be balanced by other airports, said the CSO.
Cork is Ireland's second largest city located in the country's south and Shannon is a major city along the western coast of Ireland.
In Q3 2019, nearly 85 percent of passengers handled by Irish airports were travelling to and from Europe, said the CSO, adding that the two most popular countries of origin and destination were Britain and Spain.
Outside Europe, the United States was the most popular country of origin and destination, it said.
The CSO figures also showed that a total of 37,677 tons of freight were handled by Irish airports in the third quarter of this year, 95 percent of which was international freight.
In the first three quarters of this year, Irish airports handled a total of 29.51 million passengers, up 5 percent over a year ago, said the CSO.