There are 5 US Post Offices in Washington County serving a total of 23,092 residents equating to 4,618 residents per post office. It's estimated that approximately 36,857 packages are handled across the 5 county post offices annually. Washington County is a county located in the state of Florida. As of the 2010 census, the population was 24,935. Its county seat is Chipley. Washington County is a prohibition or entirely dry county, meaning that the sale of alcoholic beverages is banned in the county."