There are 2 US Post Offices in Lanier County serving a total of 7,616 residents equating to 3,808 residents per post office. It's estimated that approximately 12,156 packages are handled across the 2 county post offices annually. Lanier County is a county located in the U.S. state of Georgia. As of the 2010 census, the population was 10,078. The county seat and only incorporated municipality is Lakeland. The county is named after the Georgia poet Sidney Lanier. Lanier County is part of the Valdosta, GA Metropolitan Statistical Area. Lanier shares Moody Air Force Base with Lowndes County on its western boundary.