WOW, an Icelandic budget airline, is to start fares from US to Ireland for less than $350 return, including all taxes.
The airline will start the flights in October. They will fly from Boston and Washington DC, and have a stop over in Reykjavik, Iceland's capital.
By comparison direct flights from other airlines at at the moment are $850 around that time of year.
The flights will operate on Tuesdays, Thursdays, and Sundays and will have a two-hour stopover both ways, the Irish Times has reported.
Dublin/Reykjavik flights begin on June 2 this year.
The length of the Boston flight will be 12 hours including the stopover while Washington will be 12 hours 45 minutes.
WOW Air was voted seventh best cheap airline in the world. WOW, which uses A320 and A321 craft, was started by Icelandic entrepreneur Skúli Mogensen.
“Our aim is to transform low-cost transatlantic flights and make travel to the US affordable for everybody,” he said.
The airline had earned a good flying reputation. It flew its one millionth passenger in December 2014.
Prior to founding WOW air Mogensen spent 20 years as an entrepreneur and investor, primarily in the Technology, Media and Telecom Industry, in North America and Europe.
He co-founded and was the CEO of OZ Communications, a mobile software company and sold over 100 million copies of its messaging software to all the major handset manufacturers and mobile operators before selling OZ to Nokia in 2008.