Michael Brian Brennan

Michael B. Brennan is an active United States circuit judge on the Seventh Circuit and has served as its chief judge since 2025. Appointed by President Donald J. Trump, he entered federal appellate service in 2018 after a career that combined private practice, state‑level trial judging, and extensive work as a prosecutor and legal scholar. His professional background includes partnership at a Milwaukee law firm, eight years on the Wisconsin Circuit Court, and numerous contributions to legal education and policy through writing, mediation, and advisory roles.

Early life and legal career

Brennan was born in 1963 and pursued higher education in the Midwest. He earned a Bachelor of Arts degree, graduating cum laude, with majors in government and philosophy from the University of Notre Dame in 1986. Continuing his studies at Northwestern University School of Law, he obtained a Juris Doctor in 1988. While at Northwestern, Brennan held the position of coordinating note and comment editor for the law review and was recognized as the winner of the Julius H. Miner Moot Court Competition.

Following graduation, Brennan began his legal apprenticeship with two federal clerkships. From 1989 to 1991 he served as a law clerk to Chief Judge Robert W. Warren of the United States District Court for the Eastern District of Wisconsin. Several years later, between 1995 and 1997, he clerked for Judge Daniel Anthony Manion on the United States Court of Appeals for the Seventh Circuit, gaining early exposure to appellate practice.

Brennan entered private practice as a litigation associate with Foley & Lardner LLP in Milwaukee, where he worked from 1991 until 1995. He then transitioned to public service as an assistant district attorney for Milwaukee County, taking on lead responsibilities in numerous criminal trials. His prosecutorial experience was marked by frequent first‑chair assignments and involvement in complex courtroom proceedings.

In 1999 Governor Tommy Thompson appointed Brennan to the Wisconsin Circuit Court in Milwaukee County. He assumed office in January 2000 and served until November 30, 2008. During his tenure he presided over nearly three hundred trials and managed thousands of motions across both criminal and civil matters. Brennan also held the administrative role of presiding judge for the court’s civil division, overseeing case management and procedural operations.

After leaving the bench, Brennan returned to private practice in 2009 as a partner at Gass Weber Mullins LLC. In that capacity he focused on commercial litigation and handled appeals in both federal and state courts. His practice was complemented by work as a mediator and an American Arbitration Association‑certified arbitrator. Over the course of his career, Brennan authored more than fifty articles addressing topics such as federal practice and procedure and criminal sentencing, contributing to scholarly discourse on procedural law.

From 2011 through 2017 Brennan chaired Governor Scott Walker’s Judicial Selection Advisory Committee, a body that evaluated candidates for state judicial appointments. He also founded the Milwaukee chapter of the Federalist Society, reflecting an ongoing engagement with legal professional organizations. Additional public‑service roles have included membership on the Wisconsin Legislative Council’s Special Committee on Crimes against Children and participation in the Department of Justice’s National Advisory Committee on Violence Against Women, for which he received a special commendation.

Federal appellate service

President Donald J. Trump nominated Brennan to the United States Court of Appeals for the Seventh Circuit on August 3, 2017, designating him to fill the vacancy created when Judge Terence T. Evans assumed senior status in January 2010. The nomination was returned to the President on January 3, 2018 under Senate procedural rules, prompting a renomination announced on January 5, 2018 and formally transmitted to the Senate on January 8, 2018.

The Senate Judiciary Committee conducted a hearing on Brennan’s qualifications on January 24, 2018. The committee reported his nomination out of committee on February 15, 2018 by an 11–10 vote. Subsequent floor action included a cloture vote on May 9, 2018 that passed 49‑47, followed by confirmation on May 10, 2018 with a 49‑46 tally. Brennan received his judicial commission the next day, May 11, 2018, and entered active service as a circuit judge for the Seventh Circuit.

During his time on the appellate bench, Brennan has participated in the adjudication of a broad spectrum of federal issues arising from the states within the circuit’s jurisdiction—Illinois, Indiana, and Wisconsin. In 2025 he succeeded to the role of chief judge, assuming responsibility for the administrative oversight of the court, case assignment procedures, and coordination with other branches of the federal judiciary.

Jurisprudence and legacy

While specific opinions authored by Judge Brennan have not been highlighted in publicly available summaries, his professional trajectory illustrates a blend of trial‑level experience, appellate insight, and scholarly activity that informs his judicial perspective. His background as a prosecutor and circuit judge provides him with practical familiarity with criminal procedure, evidentiary standards, and civil litigation management. The extensive writing he has produced on federal practice and sentencing suggests an ongoing engagement with the development and clarification of procedural rules.

As chief judge, Brennan oversees the efficient operation of the Seventh Circuit, guiding policy implementation, managing caseload distribution, and representing the circuit in inter‑branch matters. His leadership role places him at the center of initiatives aimed at maintaining timely resolution of appeals and ensuring consistency across district courts within the circuit’s purview.

Brennan’s contributions extend beyond the bench. Through his involvement with the Federalist Society’s Milwaukee chapter, he has facilitated dialogue among legal practitioners and scholars on constitutional and statutory interpretation. His service on state‑level advisory committees reflects a sustained interest in shaping judicial selection processes and addressing specialized policy concerns such as crimes against children and violence against women.

The combination of private practice, public prosecution, state trial judging, and federal appellate service positions Brennan as a jurist with comprehensive exposure to multiple facets of the American legal system. His career demonstrates an ongoing commitment to both the practical administration of justice and the theoretical underpinnings of procedural law. As chief judge of the Seventh Circuit, his influence will continue to shape the court’s jurisprudence and operational effectiveness for years to come.