United Airlines, Inc. is a major American airline with headquarters at Willis Tower in Chicago, Illinois. It is the 3rd largest airline in the world, measured by fleet size and route network. United operates a large domestic and international route network, with an extensive presence in the Asia-Pacific region. It is a founding member of the Star Alliance, the world's largest airline alliance with a total of 28 member airlines. Regional service is operated by independent carriers under the brand name United Express.
As of April 2025, United Airlines operates the following aircraft: Airbus A319, Airbus A320, Boeing 737, Boeing 737 Next Generation, Boeing 757, Boeing 767, Boeing 777, Boeing 787 Dreamliner, Bombardier CRJ, Bombardier CRJ700 series, Embraer E-Jet, Embraer ERJ.
United Airlines is operating flights from/to 372 airports in 75 countries: United States, Mexico, Canada, Japan, Costa Rica, Germany, Italy, Spain, United Kingdom, Guam and other destinations.