There are 9 US Post Offices in Brunswick County serving a total of 87,525 residents equating to 9,725 residents per post office. It's estimated that approximately 139,700 packages are handled across the 9 county post offices annually. Brunswick County is a county in the U.S. state of North Carolina. As of the 2010 census, the population was 107,431. Its county seat is Bolivia. Brunswick County is included in the Myrtle Beach-Conway-North Myrtle Beach, SC-NC Metropolitan Statistical Area. It was formerly part of the Wilmington, NC Metropolitan Statistical Area. Wilmington area leaders disputed the change, but unsuccessfully."