A low-cost carrier (LCC) or low-cost airline, also called no-frills, budget or discount carrier or airline, is an airline that is operated with an emphasis on minimizing operating costs. It sacrifices certain traditional airline luxuries, for cheaper fares. To make up for revenue lost in decreased ticket prices, the airline may charge extra fees such as for carry-on baggage. As of April 2020, the world's largest low-cost carrier is Southwest Airlines, which operates primarily in the United States, as well as in some surrounding areas.

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.