While 
United Airlines
, 
Delta Air Lines
, 
American Airlines
, 
British Airways
, and 
Lufthansa
have the most flights between the US and Europe, only one of them features in the top 10 list of longest non-stop routes. That is not surprising: most of the airport pairs are necessarily from the West Coast to destinations relatively deep into Europe and sometimes at the absolute periphery of the continent.
The 10 longest routes: US-Europe
They are shown below and are based on operating anytime between October 2024 and August 2025. While the list is unlikely to change soon, there is always the chance, so treat it as a snapshot as of September 30.
Naturally, all are considerably longer than the average US-Europe flight distance of 3,704 nautical miles (6,860 km).
Photo: Lukas Wunderlich | Shutterstock
Some readers may wonder why Istanbul is included, but Turkish Airlines’ ever-growing Istanbul Airport hub is on the European side of the Bosphorus and is, therefore, a European airport. As always, the distances are based on the Great Circle and may differ in real-world operations.
|
Nautical miles (km) |
Airport pair |
Airline(s) |
Comments (October 2024-August 2025); aircraft ordered by flights |
|---|---|---|---|
|
5,954 (11,027) |
Istanbul Airport-Los Angeles |
Turkish Airlines |
Double daily 777-300ER/787-9/A350-900 |
|
5,826 (10,790) |
Istanbul Airport-San Francisco |
Turkish Airlines |
12 weekly in October, 10 to 11 weekly in winter, and double daily from April; 787-9/A350-900/777-300ER |
|
5,536 (10,253) |
Istanbul Airport-Houston Intercontinental |
Turkish Airlines |
10 weekly (daily in February); 787-9/777-300ER |
|
5,522 (10,227) |
Rome Fiumicino-Los Angeles |
ITA Airways |
Six weekly in October, three to five weekly in winter, and daily next summer; A350-900/A330neo |
|
5,453 (10,099) |
Istanbul Airport-Dallas/Fort Worth |
Turkish Airlines |
10 weekly in the summer, with daily to nine weekly flights in the winter; 787-9 |
|
5,444 (10,082) |
Rome Fiumicino-San Francisco |
ITA Airways and United |
United began the route in May 2023 and is daily summer seasonal (six weekly in April); 777-200ER. ITA began the route in July 2023 and is year-round A330neo/A350-900. ITA’s frequencies vary massively, from daily in the summer down to weekly for nearly two months this coming winter |
|
5,333 (9,877) |
Vienna-Los Angeles |
Austrian Airlines |
Six times weekly summer seasonal; 777-200ER |
|
5,326 (9,864) |
Istanbul-Denver |
Turkish Airlines |
The route began in June 2024. Four weekly; A350-900 |
|
5,276 (9,771) |
Istanbul-Seattle |
Turkish Airlines |
The route began in May 2022. 10 weekly in the summer, falling to daily for most of the winter season (five weekly in February); A350-900/787-9 |
|
5,235 (9,695) |
Barcelona-Los Angeles |
Level |
Six weekly in the summer, but mainly three weekly in the winter and four weekly in April; A330-200 |
Turkish Airlines to Los Angeles
The Star Alliance member has served the long route since 2011. In the 13 years since then, US Department of Transportation T-100 data shows that Turkish Airlines
has carried more than three million roundtrip passengers and filled about 83% of seats.
According to OAG data, the longest US-Europe route in 2010, the year before Istanbul-Los Angeles began, was Rome Fiumicino to Los Angeles, served by now-defunct Alitalia. The airport pair now ranks fourth-longest.
What is its schedule?
Until October 26, the day before northern airlines switch to winter schedules based on IATA slot seasons, Turkish Airlines’ schedule is as follows, with all times local. The A350-900 does not appear until October 28, when it will replace the 787-9 (shown below).
Photo: Ancapital | Shutterstock
As you can see, the 349-seat 777-300ER is exclusively deployed on the 13:35 departure from Istanbul, which leaves in the carrier’s primary US-bound departure bank (see the image below).
- Istanbul Airport-Los Angeles: 08:00-11:40 (787-9/777-300ER) and 13:35-17:30 (777-300ER)
- Los Angeles-Istanbul Airport: 13:35-12:45+1 (787-9/777-300ER) and 19:25-18:45+1 (777-300ER)
Image: OAG
Where Los Angeles passengers went
In the year to July 2024, Los Angeles-Istanbul had around 130,000 roundtrip point-to-point passengers, meaning it was far too small to enter the California airport’s top 15 international destinations list. Obviously, nearly everyone flew on Turkish Airlines.
Much more interesting is where passengers who transited over Istanbul went. More than 300,000 people did, with Türkiye being the largest market, followed by Iran, India, Egypt, Saudi Arabia, Greece, Lebanon, Italy, Russia, and Pakistan.
Photo: Vincenzo Pace | Simple Flying
Before the Israel-Gaza war, Los Angeles-Israel was the second-largest country market, but flights are obviously suspended. The same outcome is likely to afflict Lebanon, too.
Despite the dominance of Los Angeles to wider Türkiye, no Turkish city was among the 10 leading airport-level origins and destinations. Instead, Los Angeles-Tehran was number one, followed by Cairo, Beirut, Athens, Delhi, Jeddah, Mumbai, Rome Fiumicino (despite the backtracking), Amman, and Moscow Vnukovo (despite the backtracking, with few alternative routings available given sanctions following the Ukraine war).