Ryanair has seen a 50% increase in the number of passengers booking European flights on its dedicated US website.
The low-cost airline said visitors from the US were switching from trains to planes when travelling acorss the Continent.
It said it carried more than a million US passengers across Europe this summer.
California residents flew most with Ryanair, followed by citizens of New York, Florida, Illinois and Texas, while the most popular routes booked were Dublin-Edinburgh, Athens-Santorini, Barcelona-Rome, Frankfurt Hahn-London Stansted and Dublin-Amsterdam.
Ryanair’s Robin Kiely said: "It’s clear US consumers are no longer inter-railing across the continent, but are choosing to fly, and with Ryanair’s low fares and largest route network, it’s easy to see why more customers then ever are choosing Ryanair.
"Our US website offers American customers the facility to plan their European breaks and pay in dollars, and continues to attract record visits. We look forward to carrying even more US customers in the coming months, on our US-built, all-Boeing fleet."
