The low cost airline has informed passengers booked on some of its Belfast International to London services that their flights have been cancelled.
The airline says it will reduce its service to Stansted to two flights a week from June 2.
This follows an announcement from Ryanair in March that it was reducing the number of flights for its winter schedule because of the weak UK market and the affect of APD.
At the time it announced it was axing all three of its Polish routes to Gdansk, Warsaw and Wroclaw as well as its service to Malta.
Now in emails to affected customers, the airline said the reduction in Stansted services was the result of an “operational review”. Manchester services have also been reduced.
The airline’s timetable now lists just two flights a week from Belfast International to London Stansted from June 2.
Ryanair currently operates three return flights a day between Belfast and Stansted, with an extra flight on Sundays.
The Consumer Council said it was aware of the issue and offered advice to passengers to passengers who have had their flights cancelled.
Meanwhile, disruption continues for some Flybe customers. The airline has already cancelled today’s early morning flight between Belfast City and London City.