No-frills carrier Ryanair carried 17.4 million passengers in September, a rise of 9% compared to September 2022.
Its load factor remained unchanged at 94%.
For the rolling 12 months to the end of September, the airline has carried 178.9 million passengers, up 17% year on year. The load factor for the period is 94%, up from 90% in the previous 12-month period.
The airline operated more than 97,350 flights in September.
Meanwhile, rival budget operator Wizz Air carried 5.5 million passengers last month, 21.1% up year on year, at a load factor of 92.4%.
On a 12-month rolling basis, the carrier has carried 57.6 million passengers in the year to September 30, up 40% year on year.
The load factor for the period is 90.9%, up from 84.6% in the previous 12-month period.
Also in September, Wizz Air announced a new route from Bucharest to Thessaloniki, due to commence at the end of October.