This is a photo of Michael J.P. O'Brien photo

J.P. O'Brien



Contact by email at [email protected]

t. 416-601-7896


Law School

University of Windsor

Bar Admission

Ontario, 2013

Michael O’Brien is an associate in our Litigation Group in Toronto. He maintains a general litigation practice, with an emphasis on complex commercial disputes, government and regulatory matters and professional liability. 

Michael regularly acts for clients on a variety of civil and commercial matters, as well as in regulatory and criminal proceedings. He advises corporations and individuals on their obligations in the political sector, including ethical compliance, conflicts of interest and lobbying law. An experienced advocate, Michael has appeared for clients before a variety of courts and administrative bodies in Ontario, including as trial counsel at the Superior Court of Justice. 

In addition to his practice, Michael is an active member of the American Bar Association, and is the Vice-Chair of the Business Law Section’s subcommittee on Class and Derivative Actions. He has co-authored the following book chapters: 

  • "Cross-Border & Multijurisdiction Class Actions—A Canadian Perspective" in the American Bar Association’s annually updated volume, Recent Developments in Business and Corporate Litigation (2014, 2015, 2017, 2018, 2019) (Co-author and Co-editor).
  • "Cross-Border & Multijurisdiction Class Actions—A Canadian Perspective" in Recent Developments in Business and Corporate Litigation: Class Action Law, 2016 Edition, published by the American Bar Association in July 2016 (Co-author and Co-editor). 
  • “Multijurisdictional Issues” in Defending Class Actions: A Guide for Defendants, 4th Edition, published by LexisNexis in December 2015.

While in law school, Michael was an active member of student government and the competitive moot program. He co-founded The Charter Project, a public education charity dedicated to enhancing awareness about the Canadian Charter of Rights and Freedoms. He was the recipient of a number of student awards, including the Gowlings Prize in Civil Trial Advocacy and the J.W. Whiteside Award. While articling, Michael participated in a secondment to the enforcement branch of the Ontario Securities Commission.

Michael obtained his BA (Hons) in English Literature in 2007 and his MA in English in 2010, both from the University of Waterloo. He received his JD from the University of Windsor in 2012.

Michael was called to the Ontario bar in 2013. He is a member of the Law Society of Upper Canada, the Canadian Bar Association, the Ontario Bar Association, and the American Bar Association. He remains active in the community, most recently serving as the Chair of the Board of Directors of Camp Ekon, a non-profit summer camp in Muskoka.


  • exonerate the target of an OSC insider trading investigation
  • internal investigation for major financial institution in anticipation of inquiries from government committees and commissions
  • obtain injunctive relief for publicly listed company to compel a software service provider to end a shut down of a vital service
  • successful appeal of CPSO Registration Committee decision to deny Certificate of Registration to physician, including obtaining the extraordinary order requiring the CPSO to issue the physician a Certificate of Registration
  • representation of an energy company, defending allegations of abuse of dominance made by the Commissioner in the Competition Tribunal
  • successful medical negligence trial concerning death of young man following aortic dissection
  • assist corporation prosecute multi-million dollar faithless fiduciary dispute
  • assist large financial institutional in securities misrepresentation class action
  • successful representation of physicians before the Health Professions Appeal and Review Board on multiple occasions
  • successful response to appeal from Consent and Capacity Board decision regarding patient decision-making capacity
  • successful appeal of criminal conviction of young offender charged with sexual assault
  • successful application and multi-day hearing before Consent and Capacity Board regarding end of life decision making