Denver International Airport opened on February 28, 1995, replacing Stapleton International Airport after 16 months of delays largely caused by a failed automated baggage system that cost hundreds of millions of dollars and never worked as intended. Construction began in September 1989 under then-Mayor Federico Peña, who envisioned a facility as architecturally memorable as the Sydney Opera House. The final cost reached $4.8 billion, nearly $2 billion over budget.

The airport's setting is deliberately expansive. It occupies 53 square miles of land northeast of Denver, making it the largest airport by area in North America, larger than the combined footprints of Hartsfield-Jackson, O'Hare, LAX, and Dallas Fort Worth. Its 6-runway pinwheel configuration, with 4 parallel north-south runways and 2 east-west crosswind runways, was designed to keep operations running in virtually any weather. Runway 16R/34L stretches 16,000 feet, the longest public-use runway in North America. The Jeppesen Terminal, named for aviation pioneer Elrey B. Jeppesen and designed by Fentress Bradburn Architects, is topped by a 375,000-square-foot Teflon-coated fiberglass tensile membrane roof, engineered to evoke the snow-capped Rocky Mountains.

DEN emerged as a critical midcontinent connecting hub. As of 2024, it became the largest operating hub for United Airlines, which holds roughly half of all passenger traffic at the airport. Southwest Airlines and Frontier Airlines also maintain their largest operations here. In 2025, more than 82 million passengers moved through the airport, ranking it 4th in the United States and 10th in the world. The Regional Transportation District's A-Line train, which opened in 2016, connects the airport directly to Denver's Union Station downtown.