Howth / Sutton peninsula is located just seven miles by car from Dublin airport.
You can take a taxi from the airport (cost about €20/25) and be out to Howth in 20 minutes.

Alternatively you can get to Howth using the Dublin Bus network. Take an Airlink bus into the city centre and then take a 31 or 31B bus from Eden Quay along the Liffey's north bank out to Howth. Journey time from the city centre is about forty five minutes.

Alternatively take a DART form the city centre northbound to Howth station.

Aer Lingus and Ryanair are the national carriers and serve a variety of destinations.