Southwest Airlines Co. is a major airline in the United States that operates on a low-cost carrier model. It is headquartered in Love Field, Dallas, Texas, within the Dallas–Fort Worth metroplex, and has scheduled service to 121 destinations in the United States and 10 additional countries. As of 2018, Southwest carried more domestic passengers than any other United States airline. It is currently the third largest airline in North America based on passengers flown.

An airline hub or hub airport is an airport used by one or more airlines to concentrate passenger traffic and flight operations. Hubs serve as transfer points to help get passengers to their final destination. It is part of the hub-and-spoke system. An airline may operate flights from several non-hub (spoke) cities to the hub airport, and passengers traveling between spoke cities connect through the hub. This paradigm creates economies of scale that allow an airline to serve city-pairs that could otherwise not be economically served on a non-stop basis. This system contrasts with the point-to-point model, in which there are no hubs and nonstop flights are instead offered between spoke cities. Hub airports also serve origin and destination (O&D) traffic.