Freethinkers Hall, also known as Park Hall, is a meeting hall in Sauk City, Wisconsin. Designed by Alfred Clas, Freethinkers Hall was built in 1884 for the local Freethinkers congregation, or Freie Gemeinde in German. The congregation had been formed by German immigrants in 1852, and became the last extant Freethinker congregation in North America. It affiliated with the American Unitarian Association in 1955. The group meets in the hall to this day.