Washington Dulles Airport is the largest airport in the Washington Metropolitan Area and is one of the country's busiest airports with over 23 million passengers a year. On a typical day, more than 60,000 passengers depart Washington Dulles to more than 125 destinations around the world.

Washington D.C. is served by two primary airports that vary significantly in size and purpose. Dulles International (IAD) is the "big" one, sprawling over roughly 13,000 acres (about 20 square miles). It serves as a major international hub with five concourses and massive capacity for long-haul jets. In contrast, Ronald Reagan National (DCA) is much smaller at about 860 acres. While DCA is more convenient for its proximity to downtown D.C., it is space-constrained and handles primarily domestic flights. In 2026, Dulles remains the primary gateway for global travelers, while Reagan operates at its absolute physical limit, serving over 25 million passengers annually on the busiest runway in America despite its compact footprint.