As of the census of 2000, there were 16,658 people, 6,123 households, and 4,255 families residing in the county. The population density was 42 people per square mile (16/km²). There were 7,130 housing units at an average density of 18 per square mile (7/km²). The racial makeup of the county was 36.47% White, 62.50% Black or African American, 0.16% Native American, 0.19% Asian, 0.01% Pacific Islander, 0.14% from other races, and 0.53% from two or more races. 0.71% of the population were Hispanic or Latino of any race.
There were 6,123 households out of which 31.10% had children under the age of 18 living with them, 43.60% were married couples living together, 21.30% had a female householder with no husband present, and 30.50% were non-families. 27.80% of all households were made up of individuals and 11.60% had someone living alone who was 65 years of age or older. The average household size was 2.55 and the average family size was 3.10.
In the county, the population was spread out with 25.40% under the age of 18, 12.90% from 18 to 24, 24.60% from 25 to 44, 23.20% from 45 to 64, and 13.90% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 88.70 males. For every 100 females age 18 and over, there were 84.00 males.
The median income for a household in the county was $24,007, and the median income for a family was $29,360. Males had a median income of $25,524 versus $19,191 for females. The per capita income for the county was $12,584. About 23.90% of families and 27.80% of the population were below the poverty line, including 35.00% of those under age 18 and 25.80% of those age 65 or over.
Due to numerous municipalities in Bamberg County with low household incomes and poor tax bases, speed traps have become an established means of generating revenue for many of the small towns. A prime example of this is Denmark, where, due to the very low household income—close to three times less than that of the overall U.S. household average income—the local government has resorted to using at least one speed trap to enhance its revenue. A documented one is located on State Highway 70 near Wisteria Street. Leaving town, the 30 mph through-town speed limit changes to 45 on an uphill curve (conversely, entering town from the 45 mph highway speed, it abruptly changes to 30 mph on a downhill curve) with no notice or warning. The local police wait in a ditch nearby behind a hill. As little as a few miles above speed limit earns a ticket.