Knox County Regional Airport (IATA: RKD, ICAO: KRKD, FAA LID: RKD) is a county owned, public use airport in Knox County, Maine, United States. It is located three nautical miles (6 km) south of the central business district of Rockland, Maine. The airport serves the residents of midcoast Maine with commercial and charter aviation services. Scheduled airline service is subsidized by the Essential Air Service program.