Northwest Airlines, Inc. (often abbreviated NWA) is the principal subsidiary of Northwest Airlines Corporation (nyse: NWA) and is a major United States airline headquartered in Eagan, Minnesota, near Minneapolis-St. Paul International Airport in the United States. Northwest has three major hubs in the United States: Detroit Metropolitan Wayne County Airport, Minneapolis-Saint Paul International Airport, and Memphis International Airport. Northwest also operates flights from a hub in Asia at Narita International Airport near Tokyo and also operates transatlantic flights in cooperation with partner KLM from Schiphol Airport in Amsterdam. Additionally, it maintains focus city operations at Indianapolis International Airport and Seattle-Tacoma International Airport.

As of 2006 Northwest was the world's sixth largest airline in terms of domestic and international scheduled passenger miles flown and the U.S.'s sixth largest airline in terms of domestic passenger miles flown. In addition to operating one of the largest domestic route networks in the U.S., Northwest carries more passengers across the Pacific Ocean (5.1 million in 2004) than any other U.S. carrier, and carries more domestic air cargo than any other American passenger airline. It is the only U.S. combination carrier (passenger and cargo service) operating dedicated Boeing 747 freighters. The airline, along with its parent company, Northwest Airlines Corporation and subsidiaries, operated under Chapter 11 bankruptcy protection which, in the United States, allows continued operation during the reorganization effort, not cessation of flights as in the case in some countries. Northwest emerged from bankruptcy protection on May 31, 2007.

Northwest Airlines' regional flights are operated under the name Northwest Airlink by Mesaba Airlines, Pinnacle Airlines, and Compass Airlines. Northwest Airlines is currently a minority owner of Midwest Airlines, holding a 40% stake in the company. Its frequent flyer program is called WorldPerks. Northwest Airlines' tagline is "Now you're flying smart."

On April 14, 2008, Northwest announced it will be merging with Delta Air Lines, subject to regulatory review. If approved, the new airline will retain only the Delta Air Lines name and brand, and become the largest airline in the world.

Beginnings

Northwest Airlines was founded on September 1, 1926 by Colonel Lewis Brittin, under the name Northwest Airways. Like other early airlines, Northwest's focus was not in hauling passengers, but in flying mail for the U.S. Post Office Department. The fledgling airline established a mail route between Minneapolis and Chicago, using open cockpit biplanes such as the Curtiss Oriole.

. Northwest stock began to be publicly traded in 1941.