There are 40 US Post Offices in Luzerne County serving a total of 243,115 residents equating to 6,078 residents per post office. It's estimated that approximately 388,039 packages are handled across the 40 county post offices annually. Luzerne County is a county located in the U.S. state of Pennsylvania. As of the 2010 census, the population was 320,918. Its county seat is Wilkes-Barre. Luzerne County is included in the Scranton\u2013Wilkes-Barre\u2013Hazleton, PA Metropolitan Statistical Area."