Plum Branch is a town in McCormick County, South Carolina, United States.

[5] According to the United States Census Bureau, the town has a total area of 0.4 square miles (1.0 km2), all land.

As of the 2010 Census, the population was 82, 59 (71.95%) were White, 20 (24.39%) were Black or African American, and 3 (3.66%) were two or more races.

None were Hispanic or Latino (of any race)[7] At the 2000 census there were 98 people, 43 households, and 26 families living in the town.

There were 10.3% of families and 21.9% of the population living below the poverty line, including 26.7% of under eighteens and 35.0% of those over 64.