Judge Michael Brennan is a resident of Marshfield, Wisconsin. He graduated from the University of Wisconsin-Eau Claire, and from the University of Wisconsin Law School in 1964. He practiced law in Marshfield until he was appointed as a nonpartisan County/Circuit Court Judge in Clark County by Governor Patrick Lucey. He later ran for election and served on the bench from 1971 to 1999. Since his retirement in 1999, he has served as a reserve judge.
Judge Brennan was nominated by the Government Accountability Candidate Committee and appointed as one of the first six Government Accountability Board members in 2008 by Governor Jim Doyle for a term to expire May 1, 2014. His appointment to the Board was confirmed by the State Senate in 2008. He has never held partisan elected office.
He was chairperson of the G.A.B. in 2009, and serves as Board secretary for 2013.