Ryanair boss Michael O'Leary has told staff the airline has 500 more pilots and 400 more cabin crew than required and job losses will be announced in coming weeks.
Mr O'Leary made the comments in an internal video to staff after the company's financial results for the three months to June 30 were released.
He said job cuts would take place at around the end of September and again after Christmas.
Earlier this month, Ryanair cut the number of 737 MAX jets it expects to fly next summer from 58 to 30 due to delivery delays.
The airline had an average of 14,000 flight staff in the year to March 31, according to its annual report.
