Norwegian Air will begin flying between London Gatwick and Chicago and Austin from March 2018.
Seats are already on sale and start at $174 one way from Chicago and from $249 from Austin. Both routes will be operated by Boeing 787 Dreamliner aircraft.
There will be four flights a week to Chicago, starting on March 25, and three flights a week to Austin, starting on March 27.
Norwegian CEO Bjorn Kjos said: "Once again we have put the UK at the heart of our ambitious expansion plans, with affordable fares to another two exciting US destinations. As America’s third biggest city, Chicago is perfect addition to our growing networks while Austin has also become a major hub for leisure and business travel so we are delighted to offer passengers more choice and lower fares to these vibrant cities.
"Many people said low-cost long-haul would never work but three years, 13 routes and 1.5 million UK passengers later and Norwegian has shown there is huge demand for more affordable long-haul travel."
"The addition of new flights to Chicago and Austin also means that Gatwick’s long haul network breaks yet another world record as we now offer 62 long haul routes – more than any other single runway airport in the world – and the fifth largest network of any airport in Europe," said Stewart Wingate, London Gatwick Airport CEO.
Norwegian also announced new routes from Paris to Boston and Oakland, CA, as well as increased flights on existing routes from Paris to New York and LA.
