Continental Airlines was a major airline in the United States that operated from 1934 until its merger with United Airlines in 2012. It had ownership interests and brand partnerships with several carriers.

United Airlines, Inc. is a major American airline headquartered at the Willis Tower in Chicago, Illinois. United operates an extensive domestic and international route network across the United States and all six inhabited continents primarily out of its eight hubs, with Chicago–O'Hare having the largest number of daily flights and Denver carrying the most passengers in 2023. Regional service is operated by independent carriers under the brand name United Express.