I have an ICAO licence with B737NG type rating and applied to Ryanair last year. Here's the answer that I got from the guy at McGinley (November 2016):
"Thank you for your application to Ryanair. Presently we are not recruiting type-rated first officers. However, when we do start hiring applicants do need to have an EASA/JAA licence. We would not be able to accept your application if you hold an ICAO licence."
What I heard is that for captains they're accepting non EASA licence but the pilot has two years to convert his/her licence into an EASA one. Don't know if it's true.