Brien T. O'Connor


  • JD, cum laude, University of Pennsylvania Law School, 1985
  • BA, magna cum laude, Yale University, 1981


  • Massachusetts, 1985

Court Admissions

  • U.S. Court of Appeals for the First Circuit
  • U.S. Court of Appeals for the Eleventh Circuit
  • U.S. District Court for the District of Massachusetts
  • Chief Judge Andrew A. Caffrey, U.S. District Court for the District of Massachusetts (1985 - 1986)
  • American Bar Association
  • American Bar Association White Collar Crime Section, Northeast Region Co-Chair
  • Boston Bar Association
  • Boston Bar Association White Collar Crime Section
  • Benchmark Litigation: Top 100 Trial Lawyers (2018)
  • Chambers USA: America's Leading Lawyers for Business (2006-2020)
  • LMG Life Sciences Government Investigations Attorney of the Year (2017)
  • Best Lawyers’ Boston – Biotechnology Law “Lawyer of the Year” (2017, 2021)
  • Law360 “Legal Lion” (May 2016) 
  • Legal 500 - Litigation (2017)
  • The Best Lawyers in America (2009-2021)
  • LMG Life Sciences: “Life Sciences Star” (2013-2017)
  • Benchmark Litigation: Massachusetts Litigation Star (2011-2016) 
  • Who’s Who Legal: Investigations (2015-2016)
  • Massachusetts Super Lawyers (2004-2020)
  • Expert Guides’ Guide to the World’s Leading White Collar Crime Lawyers (2014)
  • Massachusetts Lawyers Weekly, Lawyer of the Year (2012) 
  • National Association of Criminal Defense Lawyers, “The Most Effective Opening Statement Ever Given?” (2012)
  • American Lawyer's “Big Suits” (2006, 2009) 
  • Department of Justice – John Marshall Award for Trial of Litigation (1996)

Brien T. O'Connor


Brien O’Connor is an accomplished trial lawyer who has also negotiated some of the most significant corporate criminal and civil resolutions in the country. Widely recognized as one of the nation’s leading white collar defense lawyers, Brien has been characterized by Chambers USA as “a hugely experienced and well-respected litigator who delivers both quality service and quality result.”

Brien focuses his practice on representing corporations and individuals in government investigations and litigation, including civil False Claims Act cases. He regularly counsels clients on matters involving alleged health care fraud and abuse, securities fraud, tax crimes, export law violations, and other fraud and corruption. He has successfully litigated numerous civil and criminal cases, including multi-district civil litigation and False Claims Act cases. Brien also conducts internal investigations and compliance reviews for corporate clients.

A former Assistant U.S. Attorney for the District of Massachusetts and Chief of that office’s Public Corruption and Special Prosecutions Unit, Brien spent 10 years investigating and prosecuting cases involving complex securities, health care, insurance, tax and bank fraud; drug trafficking, money laundering and RICO violations; and public corruption and other federal crimes. Brien has successfully tried numerous cases to juries and successfully handled several federal appeals.

Brien has been a member of the firm’s Policy Committee since 2013 and is former co-head of the firm’s Government Enforcement practice group.


Presentations & Publications

  • Moderator, “The Enforcers Speak: U.S. Attorney’s Office Roundtable,” American Conference Institute’s 17th Annual Conference on Fraud and Abuse in the Sale and Marketing of Drugs, Devices, and Medical Technology, Boston, MA (March 2017)
  • Panelist, “False Claims Act Enforcement Trends in the Healthcare Industry,” American Conference Institute’s 4th Advanced Forum on False Claims and Qui Tam Enforcement, New York, NY (January 2017)
  • Panelist, “Off-Label Prescription Use: An Access Issue,” Boston Bar Association, Boston, MA (November 2016)
  • Panelist, “Voir Dire – The Science and Considerations of Effective Jury Selection,” Q1 Productions Pharmaceutical and Medical Device Legal and Compliance Forum, Alexandria, VA (March 2014)
  • Panelist, “Managing the Unanticipated Consequences of False Claims Litigation: When Your Case Can Lead to Class Actions, Criminal Prosecution and Other Collateral Damage,” ACI’s Advanced Forum on False Claims & Qui Tam Enforcement, New York, NY (January 2014)
  • Panelist, “Handling Parallel Criminal, Civil and Administrative Investigations,” Fourteenth Annual Pharmaceutical Regulatory and Compliance Congress and Best Practices Forum, Washington, D.C. (October 2013)
  • Panelist, “Developing a Closing Argument Driven Discovery Plan,” ABA False Claims Act and Qui Tam Trial Institute, Washington, D.C. (June 2013)
  • Featured, "Q&A With Ropes & Gray's Brien O'Connor," Law360 (June 2013)
  • Moderator, Enforcer’s Roundtable, ACI’s 13th National Summit on Reducing Legal Risks in the Sale and Marketing of Medical Devices, Chicago, IL (May 2013)
  • Presenter, “Civil and Criminal Practice and Procedure,” MCLE Federal Court Judicial Forum, Boston, MA (April 2013)
  • Panelist, “The Rise of Qui Tam Litigation and its Impact on How Fraud Cases are Investigated and Prosecuted,” Edward Bennett Williams’ American Inn of Court Meeting, Washington, D.C. (September 2012)
  • Panelist, “Anatomy of a Health Care Fraud Case: Lessons From Stryker,” Boston Bar Association CLE – Health Care Fraud 2012, Boston, MA (April 2012)
  • Co-Chair and Panelist, “Light at the End of the Tunnel? Recent Court Cases and the Saga of Off-Label Promotion Enforcement,” ACI 12th National Forum on Fraud & Abuse in the Sale & Marketing of Drugs, Washington, D.C. (March 2012)
  • JD, cum laude, University of Pennsylvania Law School, 1985
  • BA, magna cum laude, Yale University, 1981
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