Cityjet chief executive, Christine Ourmières-Widener, is stepping down from her role at the independent airline.
Ms Ourmières-Widener took the helm at the company five years ago when it was owned by Air France and oversaw its sale by that group to German investor, Intra Aviation in 2014.
In a statement, the company said: “Christine’s tenure sees the organisation positively reshaped, with strong shareholders, improved financial position with a new board and management team in place”.
Dublin-based Cityjet's founder, businessman Pat Byrne, recently returned to the company as chairman.
The airline has been battling a sharp increase in competition on one of its key routes, Dublin-to-London City Airport, since the autumn when both British Airways and Flybe began flying the same route.
Cityjet serves airports in Ireland, Britain, and western Europe. It is one of London City Airport's biggest customers.