Southwest Airlines Co. (NYSE: LUV) is a major U.S. airline, the world's largest low-cost carrier, headquartered in Dallas, Texas. The airline was established in 1967 by Herb Kelleher and adopted its current name (Southwest Airlines) in 1971. The airline has nearly 46,000 employees as of December 2014 and operates more than 3,800 flights per day. As of 2014, it carries the most domestic passengers of any U.S. airline. As of March 2016, Southwest Airlines has scheduled service to 97 destinations in 40 states, Puerto Rico, and abroad.
Southwest Airlines has used only Boeing 737s, except for several years in the 1970s and 1980s, when it leased some Boeing 727s from Braniff. As of January 2016, Southwest is the largest operator of the Boeing 737 worldwide, with over 700 in service, each averaging six flights per day.