Dublin Airport accounted for almost 87% of the passengers who flew into or out of Ireland in the first three months of the year, according to the Central Statistics Office.
In total almost 6.7m passengers travelled through Ireland's five main airports in the first quarter of the year, an increase of 4% on the same period of 2016.
Almost 5.9m of them flew through Dublin Airport - which is an increase of 4.7% year-on-year - with London- Heathrow, London-Gatwick and Amsterdam proving to be the most popular routes.
Cork Airport was the next busiest in the country with more than 418,000 passengers travelling through its doors in the quarter - though that is down slightly on the same period of last year.
London-Heathrow and Amsterdam were also amongst the most popular routes in Cork, along with London-Stansted.
Shannon Airport's numbers fell by 4% to almost 272,000.
Ireland West Airport Knock enjoyed a 9.1% gain with more than 134,000 passengers using the facility, while Kerry Airport handled more than 59,000 passengers, which is a 0.4% gain.
According to the CSO almost nine out of every ten passengers on international flights were travelling to or from Europe during the period, with airports in Britain and Spain the most popular origin or destination.