Pilots there are set to join a major strike on Friday
Ryanair will go to a Dutch court later to try to stop pilots in The Netherlands joining a 24 hour strike.
They are set to take part in the action alongside colleagues in four other countries on Friday.
The Dutch pilots announced on Wednesday they would walk off the job, after their union said efforts to negotiate a collective labour agreement had failed.
In a statement, the Dutch Airline Pilots Association (VNV / Dutch ALPA) said: "For the last eight months the Dutch Airline Pilots Association has tried to negotiate a collective labour agreement between Ryanair and the Dutch ALPA without any result.
"This European pilot strike should be a wake up call for the Ryanair management."
It was earlier confirmed the German strike will run for 24 hours from 3.00am on Friday.
In response, the company said it was forced to cancel 250 out of over 2,400 flights scheduled for Germany on Friday.
It said the German Vereinigung Cockpit pilots union had failed to give seven days notice ahead of the strike, leaving the airline unable to minimise customer disruption.
Ryanair has now cancelled hundreds of flights with tens of thousands passengers affected.
The German and Dutch strikes coincides with pilot strikes in Ireland, Belgium and Sweden.
The strikes have already seen the airline cancel around 400 flights to/from the five countries.
Last Friday, some of Ryanair's Irish pilots held fourth strike.
The company had proposed third party mediation in a bid to resolve its dispute with the Irish pilots.
It comes amid a continuing dispute with the trade union Fórsa, over issues such as seniority and base transfers.
In a statement, Ryanair proposed former head of the Workplace Relations Commission (WRC) Kieran Mulvey as a third party mediator.
Employment law professor at Maynooth University, Michael Doherty, said the strikes could cause problems for the company's long-term business.
"The danger for Ryanair is while it might contain the number of passengers affected on Friday, people are thinking about booking October, Christmas, New Year trips.
"And the question is: are they confidence now that Ryanair will get them out of this?
"And to be honest, there isn't a great sign of any movement forwards in terms of resolution from the company side".