The Honourable Dennis O'Connor

O.C., OOnt, K.C.

Senior Counsel

[email protected]

The Honourable Dennis O’Connor, O.C., OOnt, Q.C., sat on the Court of Appeal for Ontario from 1998 to 2012 and served as the Associate Chief Justice of Ontario from 2001 until he retired in late-2012.

He also served as a deputy judge of the Yukon Supreme Court. He wrote numerous reported judgments on a wide variety of issues, including commercial, securities and insurance law. He also conducted two successful public inquiries: the Walkerton Inquiry (2000-2002) and the Maher Arar Inquiry (2004-2006).

Prior to his appointment to the Court of Appeal, Dennis was a senior counsel with Borden & Elliot (a predecessor firm of Borden Ladner Gervais) for 18 years. His practice focused on commercial and public law litigation, where he appeared as lead counsel on many major cases in Ontario and throughout Canada.



  • Appointed Magistrate in the Yukon Territory in 1973, where he served until 1976.
  • Sat as a Deputy Magistrate of the Northwest Territories.
  • Sat as a Provincial Court judge in the northern regions of British Columbia.
  • Acted as chief negotiator for the Government of Canada for the Yukon Indian Land Claim, 1980-84.
  • Served as chair of the Judicial Independence Committee and the Priorities and Planning Committee of the Canadian Judicial Council, 2007-2010.

Beyond Our Walls

Professional Involvement

  • Chair, Pro Bono Canada
  • Member, board of directors, Innocence Canada
  • Member, Arbitration Place
  • Fellow, American College of Trial Lawyers, 1991-present

Awards & Recognitions

  • Recognized in the 2024 edition of Chambers Canada – Canada's Leading Lawyers for Business (Dispute Resolution: Most in Demand - Nationwide)
  • Recognized in the 2024 (and since 2020) edition of Chambers Global - The World's Leading Lawyers for Business (Dispute Resolution: Most in Demand Arbitrators)
  • Recognized in the 2024 edition (and since 2016) of The Canadian Legal Lexpert® Directory (Commercial Arbitration), the 2023 (and since 2020) edition (Litigation: Regulatory & Public Law), and the 2021 edition (Corporate Commercial)
  • Recognized in the 2023 edition (and since 2020) of Lexpert Special Edition: Litigation
  • Recognized in the 2020 edition of Chambers Canada – Canada's Leading Lawyers for Business (Dispute Resolution: Class Action (Defence))
  • Recognized in the 2019 edition of Chambers Canada as a Most in Demand Arbitrator (Band 1)
  • Appointed Order of Ontario, 2017
  • Appointed Officer of Order of Canada, 2016<
  • The Advocates’ Society Medal, 2013
  • Toronto Lawyers’ Association Award of Distinction
  • The Canadian Civil Liberties Association Award for Excellence in Law
  • Association of Progressive Muslims of Ontario Eid-ul-Adha Award, 2008
  • Ontario Bar Association Award for Distinguished Service, 2007
  • Society of Ontario Adjudicators and Regulators Medal, 2006
  • Canadian Water Resources Association Distinguished Achievement Award, 2004
  • American Water Works Association Award of Merit, 2003
  • Received special recognition awards from the Municipality of Brockton (Walkerton) and the Ontario Municipal Water Association
  • Inducted into the Beaver Clan of the Crow Tribe at the Tauk-ee-tee-see-goo in the Yukon Territory, 1976

Bar Admission & Education

  • Ontario, 1966
  • LLB, Osgoode Hall Law School, 1964
  • Doctors of Law (Hon.), University of New Brunswick, 2013
  • Doctors of Law (Hon.), Law Society of Upper Canada, 2013
  • Doctors of Law (Hon.), University of Guelph, 2011
  • Doctors of Law (Hon.), Assumption University, 2008
  • Doctors of Law (Hon.), York University, 2007
  • Doctors of Law (Hon.), University of Western Ontario, 2003