Aer Lingus operate a three-times weekly direct flight from Dublin to Athens during the Summer 2013 season from May 1 to September 14. 

During the Summer 2013 season, Aer Lingus also operate one weekly direct flight from Dublin to the island of Corfu on Sundays (until September 22).

There are also many charter flights from Ireland to the Greek islands during the summer months.

Useful links:

Aer Lingus: www.aerlingus.com