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
  • LMG Life Sciences Government Investigations Attorney of the Year (2017)
  • Best Lawyers’ Boston – Biotechnology Law “Lawyer of the Year” (2017)
  • Law360 “Legal Lion” (May 2016)
  • Legal 500 - Litigation (2015-2016)
  • Who’s Who Legal: Investigations (2015-2016)
  • The Best Lawyers in America (2009-2017)
  • Expert Guides’ Guide to the World’s Leading White Collar Crime Lawyers (2014)
  • LMG Life Sciences: “Life Sciences Star” (2013-2014, 2016)
  • Benchmark Litigation: Massachusetts Litigation Star (2008, 2011-2016)
  • Chambers USA: America's Leading Lawyers for Business (2006-2016)
  • Massachusetts Lawyers Weekly, Lawyer of the Year (2012)
  • Massachusetts Super Lawyers (2004-2015)
  • International Who's Who of Business Crime Lawyers (2007-2013)
  • PLC Which Lawyer? Yearbook (2007, 2008, 2010-2012)
  • Euromoney’s Expert Guides: White Collar Crime Lawyers (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, a partner in the Boston office, has represented numerous well-known corporations, as well as individuals, in white-collar criminal cases and investigations and other government enforcement and regulatory matters. Brien has represented clients in matters involving alleged securities fraud, health care fraud and abuse, tax crimes, export law violations and other fraud and corruption. Brien also handles complex civil cases, some of which are related to government enforcement, and conducts internal investigations for corporate clients.

Brien rejoined Ropes & Gray in June of 1999 with ten years of experience investigating and prosecuting complex securities, health care, insurance and bank fraud, public corruption, tax, drug trafficking, money laundering, RICO violations, and other federal crimes for the United States Attorney's Office for the District of Massachusetts.

From 1996 to 1999, Brien served as Chief of Public Corruption and Special Prosecutions for the United States Attorney's Office. In 1996, he received the John Marshall Award for Trial of Litigation, the Department of Justice's top trial award, for leading a nationwide municipal securities fraud and corruption investigation that culminated in the conviction of a prominent investment banker following a three-month jury trial, and multimillion-dollar civil settlements with two leading Wall Street investment banks. Brien has successfully tried numerous cases to juries and has successfully handled several appeals in the First Circuit Court of Appeals.


  • Featured, "Q&A With Ropes & Gray's Brien O'Connor," Law360 (June 2013)


  • Presenter, “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, “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)