Directly-employed Ryanair pilots based in Ireland, who are members of the Irish Air Line Pilots' Association (IALPA), are to strike for 48 hours from midnight on 22 August.
Their union served strike notice on the company this evening, and said Ryanair pilots would notify the company of further strike days in due course.
The move comes after 94% of IALPA members voted in favour of industrial action in this dispute over pay and conditions.
Management at the airline were sitting down with representatives from the Fórsa trade union in a meeting mediated by Kieran Mulvey.
Fórsa is the parent union of IALPA, which represents 180 Dublin-based pilots who are directly employed by Ryanair.
It said that "only a substantive counter proposal from Ryanair management, which properly addressed all areas of the IALPA claim" would convince pilots not to strike next week. The union said "no such counter- proposal was made".
In a statement, Ryanair has called on pilots and Fórsa to return to independent mediation.
It branded the pilots pay proposals as "unrealistic and unimplementable", saying they amount to a 101% pay increase.
The airline also criticised the timing of this industrial action.
"Ryanair Pilots are insisting on these pay demands being met, just one day after Norwegian announced the closure of its Dublin operations with the loss of over 120 crew jobs, despite the fact that Ryanair has a surplus of over 500 pilots due to the delayed delivery of over 30 MAX aircraft this winter, and just 10 weeks before a "no-deal" Brexit could cause further disruption to air travel and airline jobs in Ireland and the UK", the statement said.
The airline's Chief People Officer said the pay claim in this dispute to would see Ryanair pilots "earn more than the President of Ireland or our Taoiseach".
Eddie Wilson said Ryanair has "done everything in our power to avoid disruption" but that "no company can concede to grossly unreasonable demands".
The industrial action will see around 180 Irish based Ryanair pilots go on strike for 48 hours next Thursday and Friday.
Fórsa says it regrets any disruption to passengers but attributed this to Ryanair's "unwillingness or inability to negotiate a fair and transparent pay package".
The dispute comes as Ryanair staff in three other European countries are set to go on strike.
Today unions representing cabin crew in Spain announced plans for 10 days of strike in September unless the airline changes its plans to close several bases in the country.
UK-based pilots who are members of the British Airline Pilots Association have voted to strike over two days on 22 and 23 August and for three more days from the 2 September.
Meanwhile, Ryanair's Portuguese cabin crew trade union members are also due to strike for five days from 21 August in a dispute over leave.