- Established: 1816
- Population: 118,560 (2000 census)
- County Seat: originally both Oswego and Pulaski, exclusively Oswego since 1852. There are still two county courthouses.
- Tourism Region: Thousand Islands-Seaway
- Information: Oswego County website
- Bordering Counties: Cayuga, Jefferson, Lewis, Oneida, Onondaga
- Area code: 315
- Origin of Name: From the Iroquois word meaning "the outpouring," referring to the mouth of the Oswego River
- Incorporated Cities: Fulton, Oswego
- Villages: Altmar, Central Square, Cleveland, Hannibal, Lacona, Mexico, Parish, Phoenix, Pulaski, Sandy Creek
- Towns: Albion*, Amboy, Boylston, Constantia, Granby, Hannibal, Hastings, Mexico, Minetto, New Haven, Orwell, Oswego, Palermo, Parish, Redfield, Richland, Sandy Creek, Schroeppel, Scriba, Volney, West Monroe, Williamstown
* This is one of two towns named Albion in New York State. The other is in Orleans County.
- Oswego County is in NYSDOT Region 3, county code 34.
- List of county highways from Empire State Roads.
- Relevant exit guides: