Passenger numbers to and from continental Europe increased by 6% as almost 1.7 million passengers travelled to and from European destinations during the month.
Almost 828,000 passengers travelled to and from UK destinations in September, which was a 1% increase over the same period last year.
The number of passengers travelling to the Middle East, North Africa and the Asia Pacific region remained flat, as almost 90,000 passengers travelled to and from these destinations last month.
Transatlantic traffic to North America increased by 4% as almost 443,000 passengers travelled on this route sector last month.
Passenger numbers on domestic routes increased by 1% with more than 9,000 travelling on domestic flights last month.
So far this year, the number of passengers using Dublin Airport as a hub to connect to other destinations has increased by 6%, with almost more than 1.5 million passengers connecting at the airport between January and September.
The latest figures mean that 25.5 million passengers (+5%) have passed through Dublin Airport in the first nine months of the year, a healthy 1.3 million more than during the same period a year ago.