Michael O'Leary believes it is "inevitable" there will be just four major airlines in Europe over the next six years.
Ryanair is the biggest in many European countries, including Ireland and the UK.
Figures show the airline made a profit of more than €1bn after tax in the year up until May.
Speaking to Reuters, Mr O'Leary said that change in the European airline market is coming.
He said: "I think it is inevitable that in the next five or six years Europe consolidates around four large carriers, each with about 20% market share.
"IAG, Lufthansa, Air France, KLM and Ryanair. Everybody else either disappears, merges, gets taken over, partners with one or other of those big four."