There are 24 US Post Offices in Oswego County serving a total of 122,420 residents equating to 5,101 residents per post office. It's estimated that approximately 195,396 packages are handled across the 24 county post offices annually. Oswego County is a county located in the U.S. state of New York. As of the 2010 census, the population was 122,109. The county seat is Oswego. The county name is from a Mohawk language word meaning \"the outpouring\", referring to the mouth of the Oswego River. Oswego County is part of the Syracuse, NY Metropolitan Statistical Area."