There are three main international airports in Ireland, which are located in Dublin, Shannon and Cork. Cork airport mostly has routes within Europe so if travelling from outside Europe you will need to fly to Dublin or Shannon. The national air carrier is Aer Lingus and Ryanair offers low budget flights to and from many European Countries. There are also two smaller airports located in Kerry and Mayo. Kerry’s Farranfore Airport serves Dublin, London and Frankfurt and Knock Airport in County Mayo has flights to and from London, Manchester and Bristol.
You can take a train to Killarney from Dublin or Cork (change at Mallow) however if you are travelling beyond here you will need to catch a bus. Buses will take you to the major towns in the county.