US Airways (formerly USAir) was a major United States airline that operated from 1937 until its merger with American Airlines in 2015. It was originally founded in Pittsburgh as a mail delivery airline called All American Aviation, which soon became a commercial passenger airline. In 1953, it was renamed Allegheny Airlines and operated under that name for a quarter-century. In October 1979, after the passage of the Airline Deregulation Act, Allegheny Airlines changed its name to USAir. A decade later it had acquired Piedmont Airlines and Pacific Southwest Airlines (PSA), and was one of the U.S.'s seven transcontinental legacy carriers. In 1997, it rebranded as US Airways.

The airline had an extensive international and domestic network, with 193 destinations in 24 countries in North America, South America, Europe, and the Middle East. The airline was a member of the Star Alliance, before becoming an affiliate member of Oneworld in March 2014. US Airways had 343 mainline jets, as well as 278 regional jet and turboprops flown by contract and subsidiary airlines under the name US Airways Express via code sharing agreements.

The airline had severe financial difficulties in the early 2000s, filing for chapter 11 bankruptcy twice in two years. In 2005, America West Airlines carried out a reverse merger, acquiring the assets and branding of the larger US Airways while putting the America West leadership team largely in charge of the merged airline.

In 2013, American Airlines and US Airways announced plans to merge, creating the largest airline in the world. The holding companies of American and US Airways merged effective December 9, 2013. The combined airline carried the American Airlines name and branding and maintained the existing US Airways hubs for a period of at least five years under the terms of a settlement with the Department of Justice and several state attorneys general. US Airways management runs the combined airline from the American headquarters in Fort Worth, Texas. On April 8, 2015, the FAA officially granted a single operating certificate for both carriers, marking the end of US Airways as an independent carrier. The brand continued to exist until October 2015.

Its first hub was in Pittsburgh, and it operated hubs in Charlotte, Las Vegas, Philadelphia, Phoenix–Sky Harbor, and Washington–Reagan.

The final US Airways flight was San Francisco to Philadelphia via Phoenix and Charlotte, operating as Flight 1939 with 1939 commemorating the birth of All American Aviation, which eventually became US Airways. Repainting of US Airways' planes into the American Airlines scheme was expected to take until "late 2016", with new flight attendant uniforms also being introduced in 2016.