Louis Armstrong New Orleans International Airport (IATA: MSY, ICAO: KMSY, FAA LID: MSY) (French: Aéroport international Louis Armstrong de La Nouvelle-Orléans) is an international airport under Class B airspace in Kenner, Jefferson Parish, Louisiana, United States. It is owned by the city of New Orleans and is 11 miles (18 km) west of downtown New Orleans. A small portion of Runway 11/29 is in unincorporated St. Charles Parish. Armstrong International is the primary commercial airport for the New Orleans metropolitan area and southeast Louisiana.
 MSY covers 1,500 acres (607 ha) of land. At an average of 4.5 feet (1.4 m) above sea level, MSY is the third lowest-lying international airport in the world, only behind Amsterdam Airport Schiphol in the Netherlands, which is 11 feet (3.4 m) below sea level, and Atyrau International Airport in Kazakhstan, which lies 72 feet (22 m) below sea level.
 Plans for a new airport began in 1940, as evidence mounted that the older Shushan Airport (New Orleans Lakefront Airport) was too small.
 The airport was originally named Moisant Field after daredevil aviator John Moisant, who died in 1910 in an airplane crash on agricultural land where the airport is now located. Its IATA code MSY was derived from Moisant Stock Yards, as Lakefront Airport retained the code NEW. In World War II the land became a government air base. It returned to civil control after the war and commercial service began at Moisant Field in May 1946. In September 1947, the airport was shut down as it was submerged under two feet of water in the wake of the 1947 Fort Lauderdale Hurricane's impact.
 When commercial service began at Moisant Field in 1946, the terminal was a large, makeshift hangar-like building—a sharp contrast to airports in then-peer cities. A new terminal complex debuted in 1959 towards the end of Mayor DeLesseps "Chep" Morrison's administration. The core of this structure formed much of the facility used until November 2019. It is situated on the south side of the airfield. The terminal contained two sections, East and West, connected by a central ticketing alley. Four concourses, A, B, C and D, were attached to the terminal, and had a total of 47 gates. The vaulted arrivals lounge at the head of Concourse C and the adjacent, western half of the ticketing alley are the remaining portions of the airport's 1959 terminal complex.
 Retired United States Air Force Major General Junius Wallace Jones served as airport director in the 1950s. During his term, the airport received many improvements. By the time the previous airport terminal building opened in 1959, the name Moisant International Airport was being used for the New Orleans facility. In 1961, the name was changed to New Orleans International Airport. In the early 1970s, the airport was expanded. A lengthened main terminal ticketing area, an airport access road linking the terminal to I-10, and Concourses A and B were constructed.
 In July 1978, National Airlines began service to Frankfurt via Amsterdam aboard McDonnell Douglas DC-10s. This was New Orleans' first transatlantic flight. Less than a month later, National added a stop in Tampa due to low demand. In May 1981, British Airways inaugurated a flight from London's Gatwick Airport to Mexico City that stopped in New Orleans. It flew a Lockheed L-1011 TriStar on the route. The airline discontinued the service in October 1982 because of financial problems.
 Northeastern International Airways operated a small hub at MSY in the spring of 1984. Another airline that attempted to operate a hub at MSY was short-lived Pride Air which was based in New Orleans and was operating nonstop or direct Boeing 727 service from the airport to sixteen destinations including cities in California, Florida, and the western U.S. in the summer of 1985.
 In July 2001, to honor the 100th anniversary of Louis Armstrong's birth (August 4, 1901), the airport's name became Louis Armstrong New Orleans International Airport.
 MSY reopened to commercial flights on September 13, 2005, after the devastation of Hurricane Katrina the previous month, with four flights operated by Delta Air Lines to Atlanta and a Northwest Airlines flight to Memphis. Slowly, service from other carriers began to resume. All international service into MSY was suspended while the FIS facility was closed post-Katrina. The facility reopened to chartered flights arriving from London, Manchester, Bournemouth, and Nottingham, UK—all carrying tourists in for Mardi Gras and set to depart aboard a cruise liner.
 MSY served 9,785,394 passengers in 2014, exceeding for the first time in the post-Katrina era the total passenger count of 9,733,179 achieved in 2004, the last full calendar year prior to Katrina's landfall in August 2005. A new record passenger count was set by the airport in 2015. 10,673,301 passengers were served, eclipsing the earlier record of 9.9 million passengers, set in 2000.
 In December 2015, the New Orleans Aviation Board, along with New Orleans Mayor Mitch Landrieu and City Council, approved a plan to build a new $598 million terminal building on the north side of the airport property with two concourses and 30 gates. Designed by world-renowned Argentine-American architect Cesar Pelli, construction on the new main terminal began in January 2016. During the construction, the scope of the project was expanded so the terminal would feature 35 gates. In March 2017, British Airways commenced nonstop service to London's Heathrow Airport on a Boeing 787. The new terminal opened in November 2019 at a cost of $1.3 billion.
 MSY has a single terminal with three concourses labeled A, B, and C. There is a total of 35 gates. Departures and Ticketing are on Level 3, TSA Security Screening is on Level 2, and Arrivals and Baggage Claim are on Level 1. International flights are processed in Concourse A, which contains the airport's customs facilities.
 The terminal is served by Interstate 10. Bus service between the airport and downtown New Orleans is provided by New Orleans Regional Transit Authority Airport Express Route 202 and Jefferson Transit bus E-2. Airport Shuttle has services to most hotels and hostels in the Central Business District of New Orleans. The rental car facility is on the south side of the airfield next to the former terminal.
  This article incorporates public domain material from the Air Force Historical Research Agency.