- Stewart International Airport is a public airport located in New Windsor, New York, United States. It is situated in the Hudson Valley, approximately 60 miles (97 km) north of Manhattan. The airport covers an area of 2,448.68 acres (990.49 ha) and has two runways. Stewart Airport primarily serves as a secondary airport for the New York City metropolitan area, offering both domestic and international flights. It is operated by the Port Authority of New York and New Jersey.