Joan Ballweg was born the oldest of four to a first generation American in West Allis, WI on March 16, 1952, and she is the state senator for the 14th District located in south central Wisconsin. Joan and her husband, Tom, live in Markesan in Green Lake County.

Joan and Tom own and operate a John Deere Farm Equipment dealership in Waupun and a yard and garden store in Beaver Dam, and they have been in that business since 1976. Joan graduated in 1974 from UW-Stevens Point, and was a first grade teacher before she and Tom went into business.

Her public service began in Markesan, where she served as alderperson on the Markesan City Council for 4 years, and then served as mayor for another 6 years. Later, she sat on the Waupun Memorial Hospital Board of Directors and was Chair from 2002 to 2004. From 2003 to 2004, she also served on the management committee of Agnesian HealthCare Enterprises. Most recently, Senator Ballweg served as the state representative for the 41st Assembly District from 2004 through 2020.