There are 5 US Post Offices in Sussex County serving a total of 9,728 residents equating to 1,946 residents per post office. It's estimated that approximately 15,527 packages are handled across the 5 county post offices annually. Sussex County is a rural county located in the Commonwealth of Virginia. As of the 2010 census, the population was 12,087. Its county seat is Sussex. It was formed in 1754 from Surry County. The county is named after the county of Sussex, England. Sussex County is included in the Greater Richmond Region.