Dublin Airport (IATA: DUB) can be found in Collinstown, 10km north of the city of Dublin, Ireland. With over 18 million passengers in 2010, the airport is the busiest in Ireland. It is the headquarters of the Irish flag-carrier Aer Lingus, Europe's largest 'cheap' airline Ryanair, and Irish regional domestic airline Aer Arann. Buses and taxis connect it to the city, with a Rapid Transit Line in development.
The airport provides flights to many cities in Ireland, Europe and the UK, including all 5 airports in London. There is a decent long-haul network from the airport too, with a range of carriers flying to popular destinations in the US and a twice daily service to Abu Dhabi.
Here are some of the major Airlines that service Dublin Airport:
The above mentioned information is taken from: http://en.wikipedia.org/wiki/Dublin_Airport