Denver International Airport (IATA: DEN, ICAO: KDEN), often called DIA, is a major international airport located in northeastern Denver, Colorado. DIA was voted the 2005 Best Airport in North America by readers of Business Traveler Magazine.

The airport's distinctive white tension fabric roof is designed to be reminiscent of the snow-capped Rocky Mountains in winter. It is also known for a pedestrian bridge connecting the terminal to Concourse A that offers a unique view of planes taxiing directly underneath. The airport is a major hub for United Airlines and Frontier Airlines, as well as the primary hub for Ted, a subsidiary of United.

Denver International Airport is 19.5 miles (31.5 km) further from downtown Denver than Stapleton International Airport, the airport it replaced. The distant location was chosen to avoid noise impacts to developed areas, to accommodate a generous runway layout that would not be compromised by winter storms, and to allow for future expansion. The 54 square miles of land occupied by the airport actually has twice the land area of Manhattan, and was transferred from Adams County to Denver after a 1989 vote, increasing the city's size by 50 percent. However, much of the city of Aurora is actually closer to the airport than the developed portions of Denver, and all freeway traffic accessing the airport from Denver passes through Aurora.

Denver International Airport has public Wi-Fi access available throughout the airport provided by AT&T/Cingular. T-Mobile HotSpot service is available in the airport lounges run by United, American, and Delta airlines.