Peter Breen serves as Executive Vice President and Head of Litigation at Thomas More Society. With over two decades of legal practice, Breen leads the firm's legal team, advocating for clients in federal and state courts across the United States. His work focuses on some of the nation’s most pressing cultural and legal battles, including defending pro-life advocates, protecting religious freedoms, and upholding constitutional rights.

An experienced attorney, Breen is known for his versatility—equally adept at arguing cases in courtrooms, debating legislative matters, and providing expert legal commentary on television and radio. Before joining Thomas More Society in 2008, he left a successful private law practice in Chicago to pursue full-time public service. Breen also served two terms in the Illinois House of Representatives, where he rose to the position of Republican Floor Leader. Breen holds a B.A. in Electrical Engineering from Vanderbilt University and a J.D. from the University of Notre Dame Law School. His expertise and commitment have made him a sought-after counsel for pastors, nonprofit leaders, elected officials, and activists nationwide.
Married to Margie since 2005, Peter is a devoted husband and father to two sons.