Duval County is a county located in the U.S. state of Florida. Its county seat is Jacksonville. Duval County was created in 1822. It was named for William Pope DuVal, Territorial Governor of Florida from 1822 to 1834. Duval county is the largest reliably Republican county in the state with 515,202 registered voters. Duval County has a total area of approximately 918 square miles of which 84% is land and 16% water. As of the 2000 census, there were 778,879 people, 303,747 households, and 201,688 families residing in Duval County, FL.