Hillsboro is the county seat of Jefferson County, and is Missouri's fifth largest county by population. The residents of Hillsboro and the adjacent area enjoy the comfort and serenity of a rural setting that is located a short drive from St. Louis, and its vast array of cultural opportunities, professional sports, fine dining, and abundant shopping. The 63050 zip code includes the town of Hillsboro (population of 1625), as well as dozens of near by residential developments. Three upscale residential lake developments are within a few miles of our city limits. Hillsboro is a progressive community looking forward to future growth and change while while preserving its rich historical heritage.