South Lebanon is a census-designated place (CDP) in Linn County, Oregon, United States,[2] comprising unincorporated land on the south side of the city of Lebanon.

[6] The population and area of the CDP decreased between 2000 and 2010 as the city limits of Lebanon expanded southward.

U.S. Route 20 runs along the northeast edge of the CDP, leading north into Lebanon and southeast 11 miles (18 km) to Sweet Home.

According to the United States Census Bureau, the CDP has a total area of 1.2 square miles (3.1 km2), all land.

17.0% of all households were made up of individuals, and 8.8% had someone living alone who was 65 years of age or older.