There are 8 US Post Offices in Shelby County serving a total of 41,664 residents equating to 5,208 residents per post office. It's estimated that approximately 66,500 packages are handled across the 8 county post offices annually. Shelby County is a county located in the U.S. state of Indiana. As of 2010, the population was 44,436. The county seat is Shelbyville."