The Dublin-based carrier said the flight cancellations were caused largely by the strike action in France and air traffic control (ATC) staff shortages, although it added that disruption from widespread thunderstorms last month were also partly to blame.
The flight cancellations compared with just 43 in May last year, it added.
Chief marketing officer Kenny Jacobs said: “Regrettably over 200,000 Ryanair customers had their flights cancelled in May because of ATC strikes (mostly French), ATC staff shortages and thunderstorms.
“Ryanair calls for immediate EU Commission action to prevent more ATC strikes and staff shortages disrupting the travel plans of Europe’s consumers this summer.”
But despite the May strike woes, Ryanair’s latest passenger traffic figures show a 6% increase in passenger numbers last month to 12.5 million.
Its load factor - a measure of how well airlines fill their planes - improved to 96% from 95% a year earlier.
The latest strike disruption comes after Ryanair’s flight cancellation debacle last September, when more than 700,000 customers were affected after it was forced to scrap flights over mismanaging pilots’ annual leave.
In May, the group - headed by outspoken boss Michael O’Leary - reported a 10% rise in full-year profits to 1.45 billion euros (£1.3 billion) in spite of last autumn’s flight cancellations.
The annual results showed revenues jumped 8% to 7.15 billion euros (£6.3 billion) for the 12 months to March 31.