New CSO figures show Shannon Airport had the second highest rate of growth of any airport in Ireland last year.
2015 also marked the third straight year of growth at the airport.
1.68 million passengers passed through Shannon last year, the highest number recorded there since 2009.
It also represents an increase in passenger numbers 125,000 or 8%.
Growth in Dublin was 15.1%, though passenger numbers at Cork dropped by 3.4%.
July was the busiest month at Clare's international airport, which saw just under 17,000 flights last year.
The figures also record slightly more arrivals than departures in both flights and passengers.
London proved the most popular destination, with Heathrow and Stansted the two most popular choices.
New York's JFK Airport rounded out the top three, followed b yGatwick, Manchester, Newark, Boston, Faro, Malago and Paris Beauvais.
