Brooke MacKenzie


Bar of Ontario, 2013


B.A., Queen's University, 2009

J.D., Queen's University, 2012

LL.M., University of Toronto, 2016

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Brooke MacKenzie has successfully advocated for her clients in appeals, motions, and administrative proceedings. She has published widely on civil procedure, legal ethics and professional responsibility, and tort law, and is regularly asked to present and provide opinions and advice on litigation issues and legal ethics. 

Prior to co-founding MacKenzie Barristers, Brooke was a litigation associate at McCarthy Tétrault LLP, where her practice focused on professional liability matters, commercial disputes, and opinions.


Brooke has appeared as counsel before the Supreme Court of Canada, Ontario Court of Appeal, Federal Court of Appeal, Ontario Superior Court, and the Federal Court. She has advised regulatory bodies and members of regulated professions on professional responsibility issues, and has represented her clients before the Law Society of Ontario, the College of Physicians and Surgeons of Ontario, and the Health Professions Appeal and Review Board.

Brooke has a particular interest in appellate advocacy, having acted in or drafted written arguments for several cases before the Supreme Court of Canada, as well as numerous motions and appeals in the Ontario Court of Appeal, Divisional Court, and Federal Court of Appeal. In addition to her advocacy practice, Brooke provides legal opinions and practical advice on legal professional obligations, including confidentiality issues, law practice management, and conflicts of interest. 

In 2017, Brooke was awarded the OBA Foundation Chief Justice of Ontario Fellowship in Legal Ethics and Professionalism Studies for her research and writing on conflicts of interest, confidentiality obligations, lawyers' duty of loyalty to their clients, and motions for the disqualification of counsel.

A prolific author, Brooke's writing on legal ethics, civil procedure, civil justice reform, tort law, and constitutional law has been widely published, including in the Supreme Court Law Review, Canadian Bar Review, Queen's Law Journal, Annual Review of Civil Litigation, and the Osgoode Hall Law Journal. She is regularly invited to speak at law schools and continuing professional development events on litigation practice and professional responsibility issues.

Brooke completed her Master of Laws degree in 2016 at the University of Toronto. Her Masters' thesis, entitled "Effecting a culture shift: An empirical review of Ontario's summary judgment reforms", examined whether amendments to the Rules of Civil Procedure regarding summary judgment achieved their intended effects. It was published in the Osgoode Hall Law Journal in 2017. 


While completing her J.D. at the Queen's University Faculty of Law, Brooke was placed on the Dean’s Honour list each year, and was awarded the Samworth Advocacy Prize and the Law Society Prize for Outstanding Academic Achievement upon graduation. An active competitor in national moot competitions as a law student, she was honoured with the Mark MacGuigan Prize for Best Oralist in the Laskin Moot, as well as two awards for factum-writing.


Brooke received her B.A. (with distinction) in theatre from Queen’s University in 2009, and her J.D. from the Queen’s Faculty of Law in 2012.


Called to the Ontario bar in 2013, Brooke is a member of the Law Society of Ontario, the Canadian Bar Association, the Toronto Lawyers' Association, and the Advocates’ Society.


  • "When your client is your employer: Challenges and solutions", presented with Richard Pfohl at the 11th In-House Counsel Summit, Law Society of Ontario (virtual), February 18, 2021.

  • "Rethinking lawyers' monopoly: How should technology that provides legal services directly to the public be regulated?", presented at the Canadian Association for Legal Ethics' Annual Conference, Dalhousie Law School (virtual), October 23, 2020.

  • "Lawyering While Social Distancing: How to comply with your professional obligations and maintain a successful practice while working from home during COVID-19", webinar presented through Osgoode Professional Development, April 9, 2020.

  • "Regulating Lawyer Advertising: A Look at the Jurisprudence from the Law Society of Ontario", presented at the Canadian Association for Legal Ethics' Annual Conference, University of Windsor Law School, October 25, 2019.

  • "Who is the Client?", presented at "Non-Tax Issues in Succession Planning", Society of Trust and Estate Practitioners: Toronto branch seminar, April 10, 2019.

  • "Innovation to Demystify and Streamline Court Processes", presented at CBA/FLSC Annual Ethics Forum, The Law Society of Ontario, as part of "Access to Justice in the Dragon's Den" panel, March 1, 2019.

  • “Explaining Disqualification: An empirical review of motions for the removal of counsel”, presented at the Canadian Association for Legal Ethics’ Annual Conference, Osgoode Hall Law School, October 26, 2018.

  • "Compliance Check-In: Rules of Professional Conduct for Litigators", presented at Sudbury Colloquium, October 11, 2018.

  • "Ten Ethical Issues That Affect Solos and Small Firms and How to Deal with Them", presented at Solo and Small Firm Conference 2018 - The 21st Century Lawyer, The Law Society of Ontario, June 7, 2018.

  • "To Appeal or Not to Appeal?", presented at Successful Civil Appeals, Ontario Bar Association, May 24, 2018.

  • "What is the Role of the Regulator over the Long Term", debate at Emerging Legal Tech and the Future of Regulation, The Law Society of Ontario, May 15, 2018.

  • "Representing the Corporation: Ethical and Professional Obligations of Corporate Counsel", presented at Corporate Law Basics, Ontario Bar Association, April 13, 2018.

  • "Advanced Roundtable on Ethics in Litigation", co-chaired with Gavin MacKenzie at the Law Society of Ontario, April 11, 2018.

  • "Summary Judgment Motions Four Years after Hryniak", presented with Mr. Justice Paul Perell, Stephen Ross, and Moya Graham at the Toronto Lawyers' Association, February 28, 2018.

  • "Trends in Medical Malpractice Appeals", presented with Gavin MacKenzie at the Ontario Trial Lawyers' Association Medical Malpractice Conference, February 16, 2018.

  • “Ethics and Professional Responsibility Issues in the Civil Litigation Process”, presented at the Queen’s University Faculty of Law (guest lecture in Civil Procedure), February 1, 2018.

  • “Complexities in the law of causation in tort”, presented at the University of Toronto Faculty of Law (guest lecture in Advanced Torts), January 10, 2018.

  • “Appeals of Personal Injury Cases”, presented with Gavin MacKenzie at the Ontario Trial Lawyers’ Association Fall Conference, November 16, 2017.

  • "Recent Changes in the Rules of Professional Conduct”, presented at The Twelve-Minute Civil Litigator, Law Society of Upper Canada, September 14, 2017.

  • “Conducting an Effective Examination for Discovery”, Co-Chair with Brendan Clancy, Ontario Bar Association, on September 12, 2017.

  • "Summary Judgment in 2016", presented with Moya Graham at The Nuts and Bolts of the Summary Judgment Motion, Ontario Bar Association, November 10, 2016.

Community Involvement & Other Activities
  • Adjunct Professor, Osgoode Hall Law School (upper-year Legal Ethics seminar) (2018-present)

  • Adjunct Faculty, Humber College Paralegal Studies degree program (teaching advocacy and civil procedure), 2016-2018

  • Amicus Curiae and volunteer duty counsel, Pro Bono Ontario

  • Avid baseball fan; completed road trips to 26 Major League ballparks (so far)

  • Onetime Jeopardy! champion