Confirming it is to establish a three-plane base at Aldergrove serving London Gatwick in the first instance, the firm said other routes would be dependent on whether there was the will to have the tax abolished.
But what has paved the way for the new base is Ryanair obtaining landing slots for Belfast flights at Gatwick, now run by Aer Lingus.
A spokesperson for Antrim and Newtownabbey Borough Council said they welcome the news as a clear vote of confidence in the Council area.
The move is expected to result in hundreds of new jobs. Both the airport and Ryanair are to be congratulated.
Niall Gibbons, CEO of Tourism Ireland, said: "This announcement is good news for tourism to Northern Ireland, as we kick off our 2016 promotional drive, particularly given Ryanair's statement to introduce additional flights this autumn".
Ryanair's rolling annual traffic rose by 17 per cent in 2015 as the airline carried a total of 101.4 million passengers previous year.
He added: "We are pleased that over 101m worldwide customers chose to fly with Ryanair in 2015, as we became the first airline to reach this global traffic landmark". "It will enhance the overall Belfast-London Gatwick service and establish it as the leading and most important London "gateway" from Northern Ireland, eclipsing Heathrow in terms of frequency of service and seat capacity".
The move marks a return to Belfast for the low-priced carrier since it quit George Best Belfast City Airport in 2010.
