William C. O'Neil

Top rated Business Litigation attorney in Chicago, Illinois

Winston & Strawn LLP

Practice areas: Business Litigation, Securities Litigation, Antitrust Litigation

Licensed in Illinois since: 2003

Education: Washington University in St. Louis School of Law

Selected to Super Lawyers: 2025 - 2026

Winston & Strawn LLP

300 N La Salle Dr
Suite 4400
Chicago, IL 60654

William C. O'Neil is a top-rated attorney who practices law in Chicago, Illinois. William O'Neil focuses on Business Litigation issues. Additionally, he also helps clients with legal issues in the following areas of law: Securities Litigation and Antitrust Litigation.

William O'Neil received Super Lawyers designation for 2025 - 2026. He was selected for this honor subsequent to undergoing an evaluation of many different factors including peer recognition and professional achievement.

He became a licensed attorney in 2003. Before practicing law, he attended law school at Washington University in St. Louis School of Law and graduated in 2000.