Portland International Airport (IATA: PDX, ICAO: KPDX) is the largest airport in the U.S. state of Oregon, accounting for 90% of passenger travel and more than 90% of air cargo. Located 4 mi (6 km) northeast of Portland, close to the Columbia River, and 20 minutes by car from Downtown, PDX is connected to the downtown business and arts districts by light rail (MAX) Red Line.

PDX has direct connections to major airport hubs throughout the United States, plus direct international flights to Canada, Mexico, Japan, and Germany. It is also a hub for flights to smaller cities in Oregon, Washington, Idaho, Montana, California and Nevada. General aviation services are provided at PDX by Flightcraft. The Oregon Air National Guard has a base located on the south side of the property.

Portland International Airport is a major hub for Alaska Airlines and Horizon Air, mainly located on Concourse A, B, and C. In 2013, a Travel+Leisure magazine readers' poll named PDX the best US airport, based on its on-time record, dining, shopping, and mass transportation into the city.