The action comes just a few months after the airline recommenced flights from Belfast City after an absence of eleven many years.
Ryanair operates routes to Malaga, Alicante, Krakow, Warsaw, Gdansk and Milan from Belfast Intercontinental.
A spokesman for the airport explained: “It is disappointing that Ryanair has now resolved to withdraw operations from the whole Northern Ireland marketplace at the close of October, having variously experienced a presence in all a few area airports in modern many years.
“It has been a challenging period for aviation and a time when people will need some balance and religion in the Northern Ireland air transportation community.”
Earlier on Tuesday, main government Michael O’Leary explained the airline was set to strike its target of carrying concerning 90m and 100m travellers for the 12 months to March 2021. It flew 149m travellers in the 12 months to March 2019.
Shares rose jumped 2.1pc to €16.forty one in London, valuing the airline at €18.6bn.