There are 7 US Post Offices in Marion County serving a total of 29,372 residents equating to 4,196 residents per post office. It's estimated that approximately 46,881 packages are handled across the 7 county post offices annually. Marion County is a county located in the U.S. state of Tennessee. As of the 2010 census, the population was 28,237. Its county seat is Jasper. Marion County is part of the Chattanooga, TN\u2013GA Metropolitan Statistical Area."