In a year that saw international travel come to a standstill, the number of flights to and from Irish airports fell by more than 178,000.
Compared to 2019, almost 30 million fewer passengers used Irish airports last year with just 95,309 flights taken.
Dublin Airport handled over 7.2 million passengers while Cork Airport saw over 525,000 passengers pass through its doors during 2020.
Over 70% of the total number of passengers travelling to and from Ireland travelled in the first three months of the year before the pandemic took hold.
According to the latest statistics from the CSO, around 90% of people taking international flights were travelling within Europe.
The most popular destination for travellers from Dublin were London-Heathrow and Amsterdam-Schipol while London Heathrow and Stansted were the most popular routes from Cork.
The UK and Spain were the busiest routes in 2020 and the US was the most popular outside of the EU.
Just 759,015 passengers travelled two and from Ireland in the final three months of 2020.
A traditionally busy period as people travel to be with loved ones over the Christmas period, there was a 91% year-on-year decrease.
In the period from October to December, 772,764 passengers travelled through Dublin Airport compared to just over eight million in 2019.
Cork Airport carried just 36,126 passengers during the third quarter of 2020 - a decrease of almost 95% on the previous year.