Ryanair, which has been hampered in its expansion plans by delays to the delivery of new Boeing planes, said it could carry 198-200 million customers this year if the new aircraft are delivered on schedule.
It said there was a risk the deliveries could “slip further”, but Mr O’Leary said he thought this was “unlikely”.
However, the airline said it would be short of about 23 Boeing 737s that were due to arrive by the end of July.
Mr O’Leary said Ryanair would receive compensation from Boeing for the delays, although it would be “modest” and did not reflect the cost to the airline of having to cut back its growth plans.
The carrier said it was continuing to work closely with the aerospace giant to improve quality and increase the pace of deliveries.
Boeing’s planes have come under intense focus once again after the company was plunged into a crisis in January when a panel on one of its aircraft blew out in mid-air.
Scrutiny over Boeing’s plane manufacturing processes has led to a slowdown in deliveries.
Boeing boss Dave Calhoun has said he will step down from the planemaker at the end of the year.
Mr O’Leary said Ryanair welcomed Boeing’s management changes, and “already we’re seeing improved quality on our aircraft deliveries but sadly not yet enough progress on accelerating those deliveries”.
Ryanair did not give any profit forecasts for the current year, saying that was “heavily dependent” upon avoiding adverse events such as the wars in Ukraine and the Middle East, extensive air traffic control disruptions or further Boeing delivery delays.