Aer Lingus and Ryanair are operating full schedules at Irish airports following delays and cancellations yesterday.
The disruption was due to a communications fault at an air traffic control centre in southern England.
The National Air Traffic Service in Britain had warned of a possible knock-on effect today from the fault and passengers were being advised to check with their airline.
However, many airports are now reporting that they have returned to normal service.
Eurocontrol, the European organisation for air navigation safety, said the problem disrupted 1,300 flights - which amounts to 8% of all air traffic in Europe.
An investigation is under way to find the exact cause of the problem.
Ryanair suffered 300 delayed flights yesterday and has demanded action to stop the problem happening again.