Mr Declan Ryan has resigned as a non-executive director of the low fares airline.
Earlier this month, Mr Ryan, a member of the family who founded Ryanair, raised €23.8 million from the sale of shares in the airline after selling four million shares at a price of €5.95.
The four million shares, representing around 0.5 per cent of the airline, were placed with a number of European financial institutions.
