St. Clair County International Airport (IATA: PHN, ICAO: KPHN, FAA LID: PHN) is a public airport owned by the government of St. Clair County, Michigan, United States.

It is located in Kimball Township, five miles (8 km) southwest of the central business district (CBD) of Port Huron.

[2] For the 12-month period ending December 31, 2021, the airport had 27,375 aircraft operations, an average of 75 per day.

For the same time period, there were 58 aircraft based on the field: 52 single-engine and 3 multi-engine airplanes as well as 3 jets.

[6] Adjacent to the airport is an 80-acre (32 ha) Michigan certified business air industrial park.