Oswego is a census-designated place (CDP) in Sumter County, South Carolina, United States.

It is included in the Sumter, South Carolina Metropolitan Statistical Area.

[5] According to the United States Census Bureau, the CDP has a total area of 1.6 square miles (4.3 km2), all land.

As of the census[3] of 2000, there were 95 people, 42 households, and 34 families residing in the CDP.

14.3% of all households were made up of individuals, and 11.9% had someone living alone who was 65 years of age or older.