There are 9 US Post Offices in Nobles County serving a total of 20,305 residents equating to 2,256 residents per post office. It's estimated that approximately 32,409 packages are handled across the 9 county post offices annually. Nobles County is a county located in the U.S. state of Minnesota. As of the 2010 census, the population was 21,378. Its county seat is Worthington. The county was formed in 1857 and organized in 1870. Nobles County comprises the Worthington, MN Micropolitan Statistical Area."