US Big 3 Airlines: Competition on Spain Routes | American, United, Delta

The three largest US carriers, American Airlines, United Airlines, and Delta Air Lines, compete closely across both domestic and international markets, and Europe remains one of their most contested markets. Over the years, each has expanded its transatlantic network with a mix of year-round and seasonal services to capture growing demand for leisure and business travel.

This year, the three airlines together are operating more than 75,000 flights to Europe and offering around 19 million seats. Indeed, Spain has recently become a key leisure destination in their transatlantic strategies. United Airlines recently expanded its network to six Spanish destinations, while American Airlines is adding more flights for the upcoming winter season. Delta Air Lines has also increased its capacity to Spain.

American Airlines Leads US Carriers With The Most Routes To Spain

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American Airlines continues to maintain the largest presence among US carriers flying to Spain. The airline operates 11 routes from six of its major hubs (New York JFK, Philadelphia, Chicago O’Hare, Dallas/Fort Worth, Miami, and Charlotte), serving both Madrid and Barcelona from all except Charlotte, which connects only to Madrid. Each route operates daily, though four are seasonal and typically pause between October and March.

This winter, however, American is bringing back two of its seasonal routes earlier than planned and increasing capacity on others. The carrier will upgauge aircraft on select flights from Dallas/Fort Worth and Philadelphia, which would make a notable expansion in transatlantic capacity to Spain.

United Airlines Now Serves The Most Spanish Destinations From The US

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While American connects the most US cities to Spain, United Airlines serves the highest number of Spanish destinations. The Star Alliance carrier has long operated flights from its East Coast hubs at Newark and Washington Dulles to Madrid and Barcelona, but has expanded in recent years to include several leisure destinations across the country. These include seasonal summer service to Málaga, Tenerife, Bilbao, and Palma de Mallorca.

It will also add Santiago de Compostela in 2026, and the new service will begin on May 22 with three weekly flights from Newark. This will mark the first regular link between the United States and the Galician city, and United will be the only carrier operating the route. Like many of its transatlantic services, the flight will run on a summer-seasonal basis to capture strong leisure demand and higher yields during peak travel months.

Tenerife is an exception. United launched the route in 2022 as a summer service but transitioned into a year-round operation in 2024, connecting Newark with the Canary Islands’ main tourist gateway. Earlier this year, it was suggested that United would end the service, with its final Europe-bound flight scheduled for May 1, 2025. However, according to Cirium, an aviation analytics company, the route will return for the winter season, resuming on December 18 to coincide with holiday travel.

Delta Will Increase Its Focus On Spain In 2026

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Delta Air Lines maintains a steady year-round presence in Spain, operating from its key hubs in Atlanta and New York JFK to both Madrid and Barcelona. During the summer months, the airline boosts capacity on its Barcelona routes to 11–12 flights per week from each hub to accommodate strong seasonal demand.

Earlier this year, Delta introduced flights between Boston and Barcelona, expanding its East Coast coverage. The carrier will further strengthen its Spanish network next year by launching a new Seattle–Barcelona route and resuming daily service to Madrid beginning May 16, 2026. The new Barcelona flights will start a few days earlier, with four weekly frequencies.

In line with its broader transatlantic expansion, all of Delta’s seasonal routes from Boston to Europe will begin earlier in 2026 than they did this year. A key factor here is the boost in frequencies planned for Barcelona-El Prat Airport.