There are 4 US Post Offices in Kewaunee County serving a total of 21,203 residents equating to 5,301 residents per post office. It's estimated that approximately 33,842 packages are handled across the 4 county post offices annually. Kewaunee County is a county located in the U.S. state of Wisconsin. As of the 2010 census, the population was 20,574. Its county seat is Kewaunee. The county was created in 1852 and organized in 1859. Kewaunee County is part of the Green Bay, WI Metropolitan Statistical Area as well as the Green Bay-Shawano, WI Combined Statistical Area."