Ryanair said its passenger numbers grew by 6% to reach a total of 12.5 million in May.
The airline's load factor - who many seats it fills on each flight - rose by 1% to 96% last month.
Ryanair noted that air traffic control strikes in Europe and staff shortages caused the cancellation of over 1,100 flights in May of this year compared to just 43 in May last year.
