Oswego is a city in Oswego County, New York, United States. The population was 16,921 at the 2020 census. Oswego is located on Lake Ontario in Upstate New York, about 35 miles northwest of Syracuse. It promotes itself as "The Port City of Central New York." It is the county seat of Oswego County. The city of Oswego is bordered by the towns of Oswego, Minetto, and Scriba to the west, south, and east, respectively, and by Lake Ontario to the north.