Martin State Airport is a joint civil-military public use airport located nine nautical miles (10 mi, 17 km) east of the central business district of Baltimore, in Baltimore County, Maryland, United States. The facility is located near the town of Middle River, Maryland  on Maryland State Highway 150 (Eastern Boulevard), near the intersection of Maryland State Highway 700 (Martin Boulevard). The Maryland Aviation Administration operates the Airport on behalf of the Maryland Department of Transportation. MTN is a general aviation relief airport.