Thomas L. Kilbride was born in LaSalle. He received a B.A. degree magna cum laude from St. Mary's College in Winona, Minnesota in 1978 and received his law degree from Antioch School of Law in Washington, D.C., in 1981.

Justice Kilbride practiced law for 20 years in Rock Island, engaging in the general practice of law, including appeals, environmental law, labor law, employment matters, and other general civil and criminal matters. He was admitted to practice in the United States District Court of Central Illinois and the United States Seventh Circuit Court of Appeals. He was elected to the Supreme Court of Illinois for the Third District in 2000 and was elected as Chief Justice of the Illinois Supreme Court in October, 2010.

Justice Kilbride is a past board member, past president and past vice-president of the Illinois Township Attorneys Association, a past volunteer lawyer and charter member of the Illinois Pro Bono Center, and a member of the Illinois State Bar and Rock Island County Bar Associations. He has served as volunteer legal advisor for the Community Caring Conference, the charter chairman of the Quad Cities Interfaith Sponsoring committee, volunteer legal advisor to Quad City Harvest, Inc., and a past member of the Rock Island Human Relations Commission.