Denver International Airport (DEN) and Southwest Airlines celebrated the 20th anniversary of Southwest’s operations at DEN, marking two decades of service that have carried more than 290 million passengers on nearly 2.4 million flights through the Mile High City. ¹ Southwest ranks as DEN’s second-largest carrier, accounting for more than 29 percent of passengers carried in 2025.

To mark the milestone, Southwest hosted a western-themed community celebration at the Legacy Building at the National Western Stock Show, bringing together community partners, Rapid Rewards members, and Southwest Business and Cargo customers — a reflection of the relationships Southwest has built across Colorado over 20 years.

On January 3, 2006, Southwest Airlines inaugurated flights from Denver to three airports — Chicago (Midway), Las Vegas, and Phoenix — with an average of 13 daily departures. In 2026, Southwest is scheduled to operate an average of 243 daily departures from Denver to 96 total destinations, including 90 destinations across 39 U.S. states, three in Mexico, two in Costa Rica, and one in Belize.

In spring 2026, Southwest expanded its Denver network with the addition of service to Knoxville, Santa Rosa, Anchorage and Destin-Ft. Walton Beach; new flights to West Palm Beach are scheduled to begin in November. ²

Denver holds the distinction as the fastest-growing airport in Southwest Airlines history. Southwest employs more than 6,500 people across Colorado, leases 40 gates at DEN on Concourse C (more than at any other airport) and has invested in the region’s infrastructure including its Denver hangar, ground support equipment and cargo operations, and Southwest University training capabilities. In 2025, Southwest contributed more than $1.5 million in community giving across Colorado to organizations, such as Colorado Gives Foundation, Downtown Denver Partnership, Latin American Educational Foundation, Cleo Parker Robinson Dance and Mile High United Way. 

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