Denver International Airport Airport codesDENKDENDEN, often called DIA, is, by land size at convert53sqmikm2, the largest international airport in the United States, and the third largest international airport in the world after King Fahd International Airport and Montreal-Mirabel International Airport. Runway 16R/34L is the longest public use runway in the United States.

In 2009, Denver International Airport was the tenth-busiest airport in the world (Worlds busiest airports by passenger traffic) by passenger traffic with 50,167,485 passengers. It was also the fourth-busiest airport in the world (Worlds busiest airports by traffic movements) by aircraft movements with 606,006 movements.

The airport is located in northeastern Denver, Colorado, and is operated by the City and County of Denver (Denver, Colorado). Denver International Airport is the busiest and largest airport in the United States without non-stop service to and from Asia, although the airport is actively seeking such flights. DIA was voted Best Airport in North America by readers of Business Traveler Magazine five years in a row (2005-2009) and was named "Americas Best Run Airport" by Time (Time (magazine)) in 2002.

Denver International Airport is the main hub for low-cost carrier Frontier Airlines and commuter carrier Great Lakes Airlines. It is also the second-largest hub for United Airlines (after Chicagos OHare International Airport), as well as a focus city for Southwest Airlines. Since commencing service to Denver in January 2006, Southwest has added over 40 destinations, making Denver its fastest-growing market.

Denver International Airport is the only airport in the United States to have designed and implemented an ISO 14001-certified environmental management system that covers the entire airport.