Justin P. O'Brien

Justin P. O'Brien


Email justin.obrien@​hoganlovells.com

Phone +1 617 371 1035

Fax +1 617 371 1037

Practice groupLitigation, Arbitration, and Employment

Justin O'Brien guides clients to solutions for their most challenging commercial disputes. He develops successful strategies to avoid litigation when possible, and to build a winning case in court when necessary.

Justin is a litigator who regularly appears in state and federal courts representing clients in civil lawsuits and government enforcement actions. He investigates, negotiates, litigates, tries, and resolves matters involving commercial fraud, professional negligence, contract and license breaches, unfair business practices, and corporate misconduct.

Justin advises public and private companies and executives in a wide variety of industries, including financial services, software, education, health care, pharmaceuticals, and medical devices. He also represents clients from the engineering, construction, telecommunications, manufacturing, and retail sectors.

Justin served as a law clerk to the Honorable Patti B. Saris on the United States District Court for Massachusetts. He also previously worked in public affairs and government and as a political campaign organizer for candidates including U.S. Senators Edward Kennedy and John Kerry.

Awards and recognitions


Massachusetts Super Lawyers General: Litigation
Super Lawyers

2014 - 2018

General Litigation, Criminal Defense: White Collar, Business Litigation
Super Lawyers


Rising Star, General Litigation, Criminal Defense: White Collar, Business Litigation
Super Lawyers

Education and admissions


J.D., Boston College Law School, magna cum laude, Order of the Coif, 2003

B.A., Harvard University, cum laude, 1994


American Bar Association

Boston Bar Association

Federal Bar Association

Bar admissions and qualifications


Court admissions

U.S. Court of Appeals, First Circuit

U.S. District Court, District of Massachusetts

Representative experience

Won dismissal of three False Claims Act whistleblower cases in federal court.*

Won jury trial for plaintiff in state Superior Court regarding multiple fraudulent transfers of financial assets.*

Won Massachusetts Supreme Judicial Court decision setting precedent on enforcement of arbitration agreements.*

Won dismissal of federal housing fraud claims against a city and its mayor.*

Defended Central Artery Project ("Big Dig") public contractor in federal and state investigations and in civil litigation with successful pretrial resolutions of all matters.*

Won a multi-million dollar federal court verdict for utility services company in case of alleged public procurement fraud.*

Won reversal on appeal of a trial court's damages award regarding real estate finance transactions.*

Represented national health services CEO and national laboratory company in federal fraud investigations that were successfully concluded.*

*Matter handled prior to joining Hogan Lovells.

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