Pittsburgh is being added as the ninth destination served in North America by Icelandic budget carrier Wow Air.
Transatlantic flights via Reyklavik will run from Gatwick and Edinburgh from June 2017 with single fares starting at £119.99.
The first flight departs on June 16 with the year-round service running four times a week.
The approximate total journey time from Gatwick will be 11 hours, including a stopover in Iceland.
The service will be flown by Airbus A321 aircraft on Mondays, Wednesdays, Fridays and Sundays.
The expansion to Pittsburgh builds on transatlantic services to Montreal, Washington, Toronto, Boston, New York, Los Angeles, San Francisco and Miami.
Airline founder and chief executive Skúli Mogensen said: “Making exciting new destinations accessible for travellers across the world at unbeatable prices is an integral part of our ethos.
“Pittsburgh is certainly a destination on the rise and one that will appeal to a wide range of UK travellers looking to discover somewhere different, so we’re thrilled to add the destination to our route list.
“The past year has truly solidified our presence in the US, with a number of new routes launched and we look forward to continuing this fast rate of expansion.”