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

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

There were 341 housing units at an average density of 428.4 per square mile (165.4/km2).

14.3% of all households were made up of individuals, and 6.1% had someone living alone who was 65 years of age or older.

None of the families and 1.0% of the population were living below the poverty line, including no under eighteens and none of those over 64.