Plymouth is the largest town in Washington County, North Carolina, United States. The population was 4,107 at the 2000 census. It is the county seat of Washington County. Plymouth is located on the Roanoke River about seven miles (11 km) upriver from its mouth into the Albemarle Sound in North Carolina's Inner Banks region.
According to the United States Census Bureau, the town of Plymouth has a total area of 3.9 square miles (10.0 km²), of which, 3.9 square miles (10.0 km²) of it is land and 0.26% is water.
As of the census of 2000, there were 4,107 people, 1,623 households, and 1,119 families residing in the town. The population density was 1,061.7 people per square mile (409.7/km²). There were 1,829 housing units at an average density of 472.8/sq mi (182.5/km²). The racial makeup of the town was 35.04% White, 63.09% African American, 0.02% Native American, 0.61% Asian, 0.73% from other races, and 0.51% from two or more races. Hispanic or Latino of any race were 1.31% of the population.