The number of flights handled by air traffic controllers here fell 83% in May, compared to the same month last year.
In total 18,290 flights were dealt with by the Irish Aviation Authority's (IAA) team, as air traffic collapsed due to Covid-19 travel restrictions.
According to the IAA, Ireland is amongst the group of worst affected countries across Europe and has seen a larger decline in air movement than the European average.
Traffic moving through Dublin airport fell 89% in May compared to a year earlier, while Cork saw a 95% reduction in movements.
Shannon in Co Clare recorded an 87% lower level of air traffic versus May of 2019.
Over flights also fell 80%.
Peter Kearney, the IAA’s chief executive, said the figures indicate that aviation in Ireland has been particularly badly hit by the COVID-19 lockdown.
"As an exporting nation, the Irish economy depends on aviation for growth and development, more so than many other European countries," he said.
"It is important that we start to re-open aviation as soon as possible. This will protect jobs, save aviation businesses and help kick-start our economy."