San Francisco has become one of the major international gateways in the United States, with well-established links for long-haul travel across the Atlantic. The airport opened in the 1920s as Mills Field Municipal Airport of San Francisco, and transatlantic services started later in the 1950s. Trans World Airlines (TWA) was the first airline to launch European flights, beginning service to London and Paris in 1957.
Lufthansa followed soon after and became the first European carrier to operate scheduled service from Europe to the West Coast city. From there, the market continued to expand. More airlines entered, new routes were added, and the airport’s European network has grown steadily over the decades. According to scheduled data from aviation analytics provider Cirium, 
San Francisco International Airport now has European service from 16 different airlines.
San Francisco Sees Sustained European Demand
Overall, from January to October next year, airlines have scheduled more than 7,500 flights between the West Coast city and major destinations across Europe. Several carriers, including British Airways, 
Lufthansa, United Airlines, Virgin Atlantic, Air France, and KLM, have served the airport for more than two decades. Over the years, many of these airlines have adjusted their networks by adding new routes or increasing frequencies as demand has shifted.
At the same time, some carriers (such as Icelandair, Finnair, and Norwegian Air) have exited the market. That said, a number of airlines have launched new routes to the Bay Area in recent years. In 2022, German leisure carrier Condor started flying between San Francisco and Frankfurt, and the following year, Italian flag carrier ITA Airways added regular San Francisco–Rome Fiumicino service. Besides, LOT Polish Airlines is the latest carrier to join the market. From May next year, it will start four weekly flights between Warsaw and San Francisco.
United Airlines Dominates San Francisco’s European Market
Unsurprisingly, 
United Airlines is the largest operator of European flights from San Francisco. The airport is one of the carrier’s main hubs, and it has seen a 20% increase in overall United flights this year compared to last year. The carrier now serves 111 destinations worldwide from San Francisco. It is also the only US airline with nonstop service from San Francisco to Europe. The Chicago-based airline currently serves eight European cities: 
London Heathrow, Paris Charles de Gaulle, Frankfurt, Amsterdam, Barcelona, Zurich, Munich, and Rome Fiumicino.
London Heathrow is United’s busiest European destination from San Francisco. The airline launched the route in 1991, and it has remained a core part of the airline’s long-haul network ever since. It operates two daily one-way flights during the winter season, and in the summer season it increases to three daily services. Frankfurt is another key market for the carrier. It is one of United’s oldest transatlantic routes from San Francisco and continues to see steady demand.
The airline currently offers up to two daily flights to Frankfurt. Furthermore, in recent years, it has also added a few new destinations in Europe. Last year, United launched a seasonal service to Barcelona, and in 2023, it started a daily summer seasonal service to Rome Fiumicino. The airline joined the market after ITA Airways commenced the route in 2022.
Up To 20 Daily Flights: United Airlines’ 10 Most-Served European Airports
They have nearly 70% of the carrier’s European flights.
The European Airlines That No Longer Fly To San Francisco
Indeed, San Francisco has welcomed several new European carriers in recent years, but it has also lost a number of airlines and routes since the pandemic. It currently has no nonstop link to Iceland as it lost Icelandair following the COVID-19 pandemic. The airline first launched San Francisco service in 2005 using its then-new Boeing 767, but the route lasted only two years. The airline revived it in June 2018 after an 11-year gap and operated four weekly summer flights.
However, in 2020, the carrier discontinued the service again, citing weak financial performance. It is worth noting that, before Icelandair’s return, WOW Air had connected San Francisco to Reykjavik. The airline started flying to the Bay Area in 2016 with five weekly services but ended the route in 2018 as part of a broader restructuring. As we know, it ceased operations entirely in 2019. Besides, Finnair was another carrier to exit.
San Francisco was its fourth US destination, and the airline launched three weekly summer flights in 2016, but the service ended in 2020. Norwegian also left the market. Its UK subsidiary initially launched the London Gatwick service to the Bay Area in 2016, operating into Oakland, and later shifted the route to San Francisco in 2018. The airline ultimately withdrew the service during the pandemic as it retreated from long-haul flying.
