Thomas M. Harris was born in Lincoln. He received his B.A. degree from the University of Illinois and his J.D. degree from the University of Colorado. He was a civil trial lawyer from 1988 to 2007. He was appointed a judge in 2007 and elected resident circuit judge of Logan County in 2008. Judge Harris was assigned to the Fourth District Appellate Court on January 3, 2013, and elected to the court in 2018.
Judge Harris is an appointed member of the Supreme Court Commission on Access to Justice and previously served on the Special Supreme Court Committee to Study Courtroom and Judicial Security. He is a member of the Illinois Judges Association, Illinois State Bar Association, Logan County Bar Association, and the Lincoln-Douglas Inn of Court. He has served as chair of the Allerton Conference, Civil Practice and Procedure Section, and Tort Law Section of the Illinois State Bar Association.
Judge Harris served on the editorial board of the Illinois Bar Journal and as the publication's editor-in-chief. He is a past member of the board of directors of the Illinois Bar Foundation. In addition, he is a frequent speaker at professional seminars and guest lectures at the University of Illinois College of Law.