Trevor Orsinger

Trevor Orsinger

phone (312) 600-5588


Trevor Orsinger is of counsel at O’Mara & O’Callaghan and focuses his practice on financial services, government relations, and litigation.

Prior to joining O’Mara Gleason O’Callaghan, Trevor worked for the CME Group, Inc.—the world’s leading and most diverse derivatives marketplace—in their Market Regulation Department. In that role, he examined the sufficiency of evidence of commodities futures trading violations, prosecuted market participants before CME Group disciplinary panels, led settlement negotiations, worked closely with investigators, data quality analysts, and market surveillance teams to resolve cases, and served as legal counsel to Arbitration panels.

Before joining the CME Group, Trevor worked at Fermi Research Alliance, LLC. in Batavia, Illinois, which operates the Fermi National Laboratory. There Trevor monitored the laboratory’s contractual compliance with the Department of Energy. He also advised executive level personnel on employment issues, regulatory compliance, and transactional matters.

Trevor also previously worked for the U.S. Department of Defense, where he counseled senior staff on personnel matters, advised on internal investigations, and assisted the United States Property and Fiscal Office on fiscal law and government contracts. He played a key role in working with military lawyers in the Republic of Poland to develop a lawyer-to-lawyer program under the umbrella of the National Guard State Partnership Program.

Trevor began his legal career in the Cook County Public Defender’s Office in Cook County. Called by a commitment to serve in the United States military and give back to the place that gave so much to him, in 2006 Trevor entered the Air Force JAG Corps. During his time on active duty, he conducted a number of highly visible and complex federal prosecutions. In 2008, he also deployed to Baghdad, Iraq in support of the task force designed to assist the Iraqi government in rebuilding its judicial, correctional and law enforcement system. While he left active duty in 2009, Trevor continues to serve as a Lieutenant Colonel in the Air National Guard.

Trevor has authored a number of articles on a variety of legal topics, and wrote The Firefighter’s Best Friend with his brother Drew in 2003. He also the co-founded Sky Farmer, LLC, a Chicago-area technology startup that provides an affordable software platform and a mountable hardware device for farmers to survey and remotely collect real-time data about their crops.

Trevor lives in Wheaton with his wife Meg and their three children.


  • The Catholic University of America, B.Phil., 2000
  • The John Marshall Law School, J.D., 2003
  • DePaul University, MBA, 2017


  • United States Supreme Court
  • Federal Bar, Northern District of Illinois
  • United States Air Force Court of Criminal Appeals
  • Court of Appeals for the Armed Forces


  • DuPage County Bar Association
  • Chicago Bar Association
  • Pro Bono Association