Impact said it called off the strike action because Ryanair had agreed to recognise the union as the representative of its Irish-based pilots.
Ryanair said on Saturday that it would meet the German pilots' union for talks on Wednesday.
"Christmas flights are very important to our customers and we wish to remove any worry or concern that they may be disrupted by pilot industrial action next week", Ryanair Chief Executive Michael O'Leary said in a written statement.
During a conference call with the pilots, Mr O'Leary is understood to have said that the offer of union recognition from Ryanair today is genuine.
The Portuguese pilot union has requested a meeting and Ryanair has offered to meet them on Thursday December 21st.
Ryanair has agreed to recognise pilots' unions in an attempt to avert Christmas strikes in a "significant change" from its long-standing position.
Modi hopes for fruitful Winter Session
He also added that this parliament session should be held with a positive approach to move the country forward. The prime minister hoped the Winter Session of Parliament will be a productive one with constructive debates.
An upcoming Ryanair pilot strike has been suspended after the airline agreed to talks - much to the relief of those flying overseas for Christmas.
If the strike had gone ahead it would have seen the majority of the firm's captains in Ireland walk out.
The suspended industrial action had been planned with the support of 94 percent of pilots directly employed by Ryanair in Ireland.
It will bring certainty to Ryanair passengers travel plans over the Christmas period.
However IMPACT says it needs clarifications from Ryanair on how it will handle matters going forward.
In Spain, there are no strikes planned for pilots, but ground staff unions have not ruled out action on December 30.