US Airways will fly a daily direct service on the route from May 22 until September 6.
Philadelphia–Shannon is back on US Airways’ route map after a gap of nearly four years.
The B757-200 flight leaves Philadelphia (PHL) at 9.05pm to land in Shannon (SNN) at 8.40am.
From Shannon, the service takes off at 11.35am to touch down at 2.05pm.
The carrier already flies a year-round daily service from Philadelphia to Dublin (DUB) as well as a seasonal daily service from Charlotte (CLT) to Dublin.
Philadelphia joins Shannon’s schedule this summer along with Chicago, Alicante, Faro and Glasgow to bring the gateway’s destinations up to 33.
Dublin and Shannon are Ireland’s only airports with transatlantic services. Both offer pre-clearance for US customs and immigration.
Shannon now offers five US destinations – Boston, Chicago, Newark, JFK New York and Philadelphia – for the first time since 2009, according to the airport.
The revival in Shannon's connectivity has been linked to the airport’s recent separation from the Dublin Airport Authority (DAA).