United Airlines is continuing to grow its international network. The airline recently announced its summer 2026 expansion, adding new routes from Newark to Split, Bari, Glasgow, and Santiago de Compostela, as well as a year-round service from Washington Dulles to Reykjavik. Last fall, United revealed its largest-ever international expansion, introducing several lesser-known destinations.

The carrier’s pursuit of international routes dates back to the 1960s, though it wasn’t until 1983 that it launched its first international service, connecting Portland and Seattle with Tokyo. Over the years, United has steadily built one of the most extensive global networks among US airlines. Today, it flies to more than 360 destinations worldwide and serves more international airports than any other US carrier.

United’s Largest International Market Lies Just South Of The Border

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Notably, United Airlines serves more destinations in Mexico than in any other international market. The airline first began flying there more than five decades ago and has steadily expanded its presence since. It now operates to around 24 destinations across the country, including major hubs such as Mexico City (MEX) and Cancun (CUN), as well as smaller cities like Mazatlán (MZT) and San Luis Potosí (SLP). These flights are operated both by United and its regional subsidiary, United Express, with some services run by partner carriers on United’s behalf.

Unsurprisingly, Cancun is the airline’s busiest destination in Mexico, due to its strong leisure demand. United operates flights to the resort city from multiple hubs, including Houston (IAH), Newark (EWR), Denver (DEN), San Francisco (SFO), Washington Dulles (IAD), Los Angeles (LAX), Chicago O’Hare (ORD), and Cleveland (CLE). According to data from analytics provider Cirium, the airline has scheduled nearly 500 flights to Cancún this month alone, with Houston leading at around 161 departures.

Mexico City is the second-busiest destination for United, with over 4,700 flights scheduled in 2025. The airline connects the Mexican capital with Denver, Newark, Washington Dulles, Houston, Chicago O’Hare, and San Francisco. Besides, other high-demand destinations in the country include San Jose del Cabo (SJD), Monterrey (MTY), Puerto Vallarta (PVR), Queretaro (QRO), and Guadalajara (GDL). Furthermore, United’s latest expansion in Mexico includes a new service between Houston and Tepic International Airport (TPQ) in Nayarit, which is set to begin in December.

Canada Is United’s Second-Biggest International Market By Destinations

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The second-largest international market for United Airlines by destinations is Canada. As one of the founding members of Star Alliance, United has long benefited from its partnership with Air Canada to strengthen cross-border connectivity. Additionally, since the two carriers expanded their joint network in 2022, United’s Canadian presence has grown by more than 70%.

The carrier has been rebuilding and expanding its Canadian services. Last year, it reinstated flights between Halifax and Newark, Vancouver and Washington D.C., and Winnipeg and Denver, and also resumed Chicago routes to Winnipeg and Quebec City. Furthermore, earlier this year, it added Regina as a new Canadian destination.

The airline now serves around ten destinations across the country: Toronto (YYZ), Vancouver (YVR), Ottawa (YOW), Montreal (YUL), Calgary (YYC), Quebec City (YQB), Edmonton (YEG), Winnipeg (YWG), Halifax (YHZ), and Regina (YQR). Toronto remains United’s busiest Canadian destination, with the carrier operating more than 7,000 flights there this year. According to Cirium data, more than 1,700 flights are scheduled for next month, most of them from Newark and Chicago O’Hare.

United Airlines’ European Focus: Spain And Portugal Lead Its Network

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Beyond North America, the Star Alliance member serves the highest number of destinations in Europe, in Spain and Portugal. United first entered the Spanish market in 2010 with a Washington Dulles–Madrid service, followed by flights from Newark to Barcelona and Madrid in 2012. Since then, the carrier has steadily expanded its presence in the country.

It now offers flights to six destinations, a mix of year-round and leisure-focused seasonal routes. Its summer seasonal routes include Málaga, Tenerife, Bilbao, and Palma de Mallorca. Additionally, earlier this month, United announced plans to launch flights from Newark to Santiago de Compostela in 2026, bringing its total Spanish destinations to seven.

Portugal is another key market for the airline. United began flying there in 1997 with seasonal service between Lisbon and New York and has gradually expanded its footprint. The carrier now offers flights to five destinations, including Porto, Ponta Delgada, and its newly launched seasonal routes to Faro and Madeira, introduced in May and June 2025, respectively.