There are 6 US Post Offices in Livingston County serving a total of 14,533 residents equating to 2,422 residents per post office. It's estimated that approximately 23,196 packages are handled across the 6 county post offices annually. Livingston County is a county located in the northwestern portion of the U.S. state of Missouri. As of the 2010 census, the population was 15,195. Its county seat is Chillicothe. The county was organized January 6, 1837, and named for U.S. Secretary of State Edward Livingston.