Blenheim /ˈblɪnəm/ is a town in Marlboro County, South Carolina, United States.

[5] Blenheim Palace was the residence of the Duke of Marlborough, after whom Marlboro County is named.

[6] According to the United States Census Bureau, the town has a total area of 0.6 square miles (1.6 km2), all land.

41.3% of all households were made up of individuals, and 17.5% had someone living alone who was 65 years of age or older.

There were 22.6% of families and 15.5% of the population living below the poverty line, including no under eighteens and 44.0% of those over 64.