Philip J. O'Beirne Partner

T: 202.661.0900


Phil O'Beirne is a trial attorney with experience handling complex civil and criminal litigation.  He has served as counsel for corporations and individuals in complex commercial disputes, construction litigation, corporate compliance and FCPA matters, products liability, patent licensing, white collar criminal defense, and other matters.

Prior to joining Stein Mitchell Beato & Missner LLP, Phil was a litigation associate at Williams and Connolly, LLP, where he assisted in all aspects of litigation. 

Prior to entering private practice, Phil served on active duty as a judge advocate in the U.S. Army.  He spent the bulk of his time in the JAG Corps as a prosecutor, serving as lead counsel in more than a dozen courts-martial.  In 2009, Phil deployed to Kandahar, Afghanistan with the 82nd Combat Aviation Brigade. As the brigade’s trial counsel in a deployed environment, Phil was responsible for advising commanders on complex rules of engagement, international law, and criminal law issues.

Following his deployment, Phil became the Chief of Criminal Law in Fort Belvoir VA, supervising the prosecution of all criminal matters for a garrison of 22,000 personnel. In addition to these duties, he was individually selected by the Military District of Washington to prosecute high profile senior officer misconduct cases.

Honors & Awards

Top 40 under 40

2016 Top 40 Under 40, The National Trial Lawyers

Representative Matters

  • Trial counsel for leading engineering, procurement and construction contractor in a large commercial arbitration regarding a multi-billion dollar power plant project. Secured complete defense award for client after 19-day arbitration hearing.
  • Confidential arbitration: Counsel for financial technology venture capital firm in breach of contract and business tort dispute with former chief executive officer. After dispositive motions and discovery, secured settlement for client on favorable terms, which included no monies paid out to the former CEO and the former CEO reimbursing client for certain of its attorneys’ fees and litigation costs.

Academic Appointments

Visiting Faculty, Notre Dame Law School Intensive Trial Advocacy Program

901 15th Street NW, Suite 700, Washington, D.C. 20005  |  Phone: 202.737.7777
Photo of Philip J. O


  • District of Columbia
  • Virginia


  • Law clerk for the Hon. Thomas M. Hardiman, U. S. District Court for the Western District of Pennsylvania


Notre Dame Law School, J.D., cum laude

  • John Krupnik Award for Excellence in Trial Advocacy

Princeton University, A.B., History