Durham County is a county located in the U.S. state of North Carolina. As of the 2020 census, the population was 324,833, making it the sixth-most populous county in North Carolina. Its county seat is Durham, which is the only incorporated municipality predominantly in the county, though very small portions of cities and towns mostly in neighboring counties also extend into Durham County. The central and southern parts of Durham County are highly urban, consisting of the city as well as several unincorporated suburbs. Southeastern Durham County is dominated by the Research Triangle Park, most of which is in Durham County. The northern third of Durham County is rural in nature.