Daniel J. Cronin (born November 7, 1959) is an American politician and attorney who served as county board chairman of DuPage County, Illinois from December 2010 until December 2022. A member of the Republican Party, he previously served in the Illinois General Assembly from 1991 through 2010. Cronin was born in Elmhurst, Illinois. He received a bachelor's degree from Northwestern University and later graduated from the Loyola University Chicago School of Law. Cronin spent his early legal career as counsel for the Illinois House of Representatives from 1985 to 1987, then as a prosecutor in DuPage County from 1987 to 1989. Since 1991, he has worked in private practice. He comes from a family that has been politically prominent in DuPage. His father, a sports physician who ran his practice and owned a medical office building in Elmhurst, provided financing and support for Dan's campaigns. Dan's brother, an attorney, managed campaigns for Republican candidates at the state and county levels in 1994, then ran unsuccessfully for DuPage state's attorney during the 1996 elections. His sister, an accountant, previously served as city treasurer of Elmhurst and later as a member of the Illinois Liquor Control Commission; she was elected to the DuPage County Board in 2022. Cronin was elected to the House of Representatives in 1990, after defeating Republican incumbent Gene L. Hoffman on an anti-tax and anti-abortion platform. He supported cutbacks to taxes and government spending, and earned a reputation as a conservative Republican. He then ran for the Senate during the 1992 elections. Recent redistricting pitted Cronin against Ted Leverenz, an incumbent Democratic senator, in what was considered one of the "liveliest and most bitter contests" of the election season. Cronin won the election. He became chairman of the Senate's education committee, where he sponsored or debated several bills concerning reforms of Chicago Public Schools. He also sponsored legislation that restricted Medicaid funding for abortions, but the bill was vetoed by Governor George Ryan. After becoming chairman of the DuPage County Board in 2010, Cronin launched initiatives to consolidate units of local government in the county. His reforms included merging the county's election commission into the county clerk's office in 2019, with the approval of voters during a non-binding countywide referendum. Cronin was re-elected to a second term in 2014. His accomplishments included reducing the county's sales tax by 0.25 percentage points. While running for his third term in