Mason County, Illinois

county in Illinois, United States

Mason County is a county in the U.S. state of Illinois. According to the 2020 census, it had a population of 13,086.[1] Its county seat is Havana.[2] Mason County was created in 1841 and named for George Mason.


  1. "QuickFacts: Mason County, Illinois". United States Census Bureau. Retrieved August 11, 2023.
  2. "Find a County". National Association of Counties. Archived from the original on 2011-05-31. Retrieved 2011-06-07.