Marlboro County is a county located in the Pee Dee region on the northern border of the U.S. state of South Carolina. As of the 2020 census, its population was 26,667. Its county seat is Bennettsville. The Great Pee Dee River runs through it.

Bennettsville is a city located in the U.S. state of South Carolina on the Great Pee Dee River. As the county seat of Marlboro County, Bennettsville is noted for its historic homes and buildings from the 19th and early 20th centuries—including the Bennettsville Historic District which is listed on the National Register of Historic Places.