The cancelled flights are 8 per cent of the 2,400 originally scheduled. About 30,000 customers are likely to be affected.
Crews are striking in Spain, Belgium, Holland, Portugal, Italy and Germany. In a strongly-worded statement, Ryanair said the action had been called by unions "at the behest of competitor airline employees".
Ryanair’s Kenny Jacobs said on Tuesday: “We sincerely apologise to those customers affected by these unnecessary strikes on Friday, which we have done our utmost to avoid, given that we have already offered these unions recognition agreements.
"These repeated unnecessary strikes are damaging Ryanair’s business and our customer confidence.
"We hope these unions will see common sense and work with us to finalise agreements for the benefit of our pilots and cabin crew over the coming weeks without further disrupting our customers or our flights."
The airline added all affected customers have received emails or text messages informing them of the cancellation.
Ryanair cancelled hundreds of flights last year due to problems with pilot scheduling, and strikes led to more cancellations this summer.
The budget airline and pilots have wrangled over working conditions, base transfers and annual leave.
