The action arrives just 3 months following the airline recommenced flights from Belfast Town following an absence of eleven years.
Ryanair operates routes to Malaga, Alicante, Krakow, Warsaw, Gdansk and Milan from Belfast Global.
A spokesman for the airport said: “It is disappointing that Ryanair has now made the decision to withdraw functions from the full Northern Eire sector at the stop of Oct, having variously had a existence in all 3 regional airports in current years.
“It has been a hard time period for aviation and a time when consumers have to have some stability and faith in the Northern Eire air transportation community.”
Earlier on Tuesday, chief government Michael O’Leary said the airline was established to hit its focus on of carrying amongst 90m and 100m travellers for the calendar year to March 2021. It flew 149m travellers in the calendar year to March 2019.
Shares rose jumped 2.1pc to €16.forty one in London, valuing the airline at €18.6bn.