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.
The move comes after 94% of IALPA members voted in favour of industrial action in this dispute over pay and conditions.
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.
British pilots employed by Ryanair are also due to walk out on 2, 3 and 4 September.