Daniel O’Brien is a partner in the firm’s Litigation practice group who focuses on commercial litigation and complex commercial litigation matters. Dan counsels his clients on contract disputes, business torts, consumer fraud and consumer protection matters, sales and commercial transaction disputes, and corporate litigation. He also handles product liability and general litigation matters. Dan is experienced in prosecuting and defending complex litigation in both state and federal court.

Dan counsels clients through all phases of discovery, pretrial briefing and motion practice, trial preparation, and settlement strategy and negotiations.

He also assists municipal clients in various capacities and currently serves as prosecuting attorney for the City of Crestwood, Missouri.


  • Washington University School of Law  (J.D., 2016)
    • Washington University Law Review (Senior Executive Editor, 2015-2016; Staff Editor, 2014-2015)
    • Scholar in Law Award (scholarship)
    • Award for Excellence in Oral Advocacy
    • CALI Award for Highest Grade: Civil Liberties in Cyberspace Seminar, Fall 2015
  • Georgetown University  (B.A., magna cum laude, 2008)
    • Philosophy
    • Social and Political Thought


  • Missouri, 2016
  • Illinois, 2017
  • U.S. District Court, Eastern District of Missouri


Prior to attending law school, Dan worked as a litigation paralegal in Washington, D.C. for a number of years. During law school, he served as a summer associate at Armstrong Teasdale and completed an internship with the St. Louis County Office of the Prosecuting Attorney.

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