Ryanair has confirmed it will end operations at both airports in Belfast.
The low-cost carrier will cease flights from Belfast City Airport in September and from Belfast International Airport in October.
Ryanair blamed the cost of operating at the airports as well as a UK government “refusal to suspend or reduce” air passenger duty (APD).
Belfast International Airport said it was disappointed but had anticipated the move and was engaging with other airlines to replace the routes.
The airline said the aircraft it used on routes to and from Belfast would be “reallocated to lower-cost airports elsewhere in the UK and Europe for the winter schedule, which starts in November”.
A spokesperson for Belfast International said: “It is disappointing that Ryanair has now decided to withdraw operations from the entire Northern Ireland market at the end of October, having variously had a presence in all three local airports in recent years.
“It has been a difficult period for aviation and a time when consumers need some stability and faith in the Northern Ireland air transport network.”
Ryanair currently offers routes from Belfast International Airport to Alicante, Malaga, Krakow, Warsaw, Gdansk and Milan.
It only recommenced flights at Belfast City Airport in May after an absence of 11 years.
The airline has been operating flights to and from eight destinations in mainland Spain, the Balearic Islands and Italy.