Ryanair said its passenger numbers in June jumped to 5.3 million from 0.4 million the same month last year when very strict Covid-19 travel restrictions were still in place.
The airline said it was seeing a 72% load factor - how many seats it fills on each flight - in June.
It added that it operated over 38,000 flights last month.
Ryanair said it flew one million passengers in April, 1.8 million in May and 5.3 million in June.
The airline's shares price was higher in Dublin trade today.