Jefferson County International Airport (IATA: TWD, FAA LID: 0S9) is a public-use airport located four nautical miles (7 km) southwest of the central business district of Port Townsend, a town in Jefferson County, Washington, United States.

[1] Jefferson County International Airport covers an area of 320 acres (130 ha) at an elevation of 110 feet (34 m) above mean sea level.

[1] For the 12-month period ending December 31, 2019, the airport had 58,100 aircraft operations, an average of 159 per day: 97% general aviation, 3% air taxi, and <1% military.

At that time there were 53 aircraft based at this airport: 49 single-engine, 2 multi-engine and 2 glider.

The Port Townsend Aero Museum is located on the grounds of the airport, with several aircraft and artifacts on display.