Justin P. O'Brien - Partner

Justin is adept at guiding clients to successful outcomes in commercial litigation, investigations, enforcement actions, compliance assessments, and business advising.  He has counseled clients in industries including financial services, telecommunications, software, social media, health care, biotechnology, pharmaceuticals, government, engineering, real estate, construction, education, and retail. 

Justin's legal experience includes matters involving contracts and licensing, corporate governance, employment, fraud, professional negligence, and regulatory compliance.  He served for a decade as outside counsel to the project management consultant for the Boston Central Artery / Tunnel Project ("Big Dig"), the largest public works project in U.S. history.  He has represented clients through trials and appeals in state and federal courts, and has won cases in a variety of forums.  He has conducted internal investigations on a range of issues for major national corporations, and has represented companies and individuals in an array of enforcement actions by state and federal agencies.

Prior Experience & Education

Prior to founding Lovett O'Brien, Justin practiced law for over fifteen years as an associate and partner at Collora LLP and a partner at Hogan Lovells US LLP in Boston.  He also served as a law clerk to Judge Patti B. Saris on the U.S. District Court in Boston.  Before becoming an attorney, Justin worked in government and public affairs, and as an aide to elected officials including U.S. Senators Edward Kennedy and John Kerry.  

Justin received his B.A. in History cum laude from Harvard University.  He received his J.D. magna cum laude from Boston College Law School, where he was inducted into the Order of the Coif, served as Managing Editor of the Boston College Law Review, and received the Privitera Commencement Award for outstanding scholarship and exceptional contributions to the school.  He is originally from Brookline, Massachusetts.

Professional Achievements

Justin serves as Co-Chair of the Business and Commercial Litigation Section of the Boston Bar Association, and has served as chair of committees of the American Bar Association.  He has served on the faculty of programs for the American Bar Association, Boston Bar Association, Massachusetts Continuing Legal Education, Harvard Law School, Suffolk University Law School, and Boston College Law School.  Justin has written publications for Massachusetts Lawyers Weekly, Massachusetts Continuing Legal Education, and Bloomberg News, and has provided legal commentary in the Boston Globe and Massachusetts Lawyers Weekly.

Justin has been recognized annually since 2009 in New England Super Lawyers as one of the top lawyers in Massachusetts for his experience in business litigation, general litigation, and white collar criminal defense.  He was recognized in The Best Lawyers in America 2025 for Commercial Litigation.  He has also been included in The Irish Legal 100 as a distinguished American attorney of Irish heritage.