Ryanair will launch three new routes from Knock next year and will increase frequencies from the airport to London.
It said the decision was taken after the Irish Government agreed to scrap its €3 air tax from April 2014.
The three new routes, starting in April, are to Eindhoven, Glasgow Prestwick and Kaunas.
Knock to London routes will increase from 16 to 18 flights per week.
"The scrapping of the travel tax will help restore Ireland’s competitiveness and attractiveness to overseas visitors from the UK and Continental Europe in particular," said Ryanair’s Michael Cawley.
"Having met with all five of the main Irish airports, and announced new growth for 2014 at Shannon and Knock, we hope to announce further new route and traffic growth plans over the coming weeks."
