Williamsburg, county, eastern South Carolina, U.S. It is bordered to the south by the Santee River, and the Great Pee Dee River touches the northeastern extremity; the county is also drained by the Black River. Williamsburg county is an agricultural region in the Coastal Plain, with swamps along its rivers. Much of the land is covered in pine and lowland hardwood forests.

In 2019, Williamsburg County, SC had a population of 31.3k people with a median age of 43 and a median household income of $32,485. Between 2018 and 2019 the population of Williamsburg County, SC declined from 31,794 to 31,324, a −1.48% decrease and its median household income grew from $32,351 to $32,485, a 0.414% increase.

98.9% of the residents in Williamsburg County, SC are U.S. citizens.

The largest universities in Williamsburg County, SC are Williamsburg Technical College (110 degrees awarded in 2019).

In 2019, the median property value in Williamsburg County, SC was $68,300, and the homeownership rate was 73%. Most people in Williamsburg County, SC drove alone to work, and the average commute time was 30.4 minutes. The average car ownership in Williamsburg County, SC was 2 cars per household.

Williamsburg County, SC borders Berkeley County, SC, Clarendon County, SC, Florence County, SC, Georgetown County, SC, and Marion County, SC.