The latest in a series of winter sales that have seen over two million seats discounted since November, this one runs to midnight on Sunday, December 20.
The sale includes 500 European routes, the airline says – with destinations from Dublin including Amsterdam, Cologne, Paris and London in January.
The €9.99 ‘Santa’ sale is showing on the airline’s home page as we publish, but passengers can also find it by using the Fare Finder feature.
To see the sale routes, enter your departure airport, a destination of “anywhere”, a budget of less than €10, and a travel period of January.
The sale is the latest in the winter airfare wars promised by Michael O’Leary this summer, aided by low fuel prices, rising profits and improving economies.
Earlier this month, Ryanair announced that it would carry five million customers between December 18 and January 7 across its European network.
One million extra seats have been added for the holiday season.