Doug Lennox

Doug Lennox is a senior class action lawyer at Klein Lawyers.  Based in our Toronto office, Doug has acted for plaintiffs in class actions involving defective products, breaches of securities laws, institutional abuse, hospital negligence and violations of consumer protection laws. He has appeared on behalf of class action plaintiffs in courts in Ontario, British Columbia, Saskatchewan, Manitoba, Quebec, and Newfoundland and Labrador.  He has fought for the rights of ordinary Canadians to have access to our courts, and successfully argued before the Ontario Court of Appeal the case of McIntyre v. Ontario (Attorney General), a legal challenge to Ontario’s 200-year-old ban on contingency fees, which resulted in the Ontario government finally changing this antiquated law.

Doug is a frequent writer and lecturer on class actions, and a regular contributor to The Verdict, the publication of the TLABC.

Practice Areas – Class Action

Selected Decisions

  • Parker v. Pfizer Canada Inc., [2012] O.J. No. 2867 (S.C.J.)
  • McSherry v. Zimmer GMBH, [2012] O.J. No. 3260 (S.C.J.)
  • Stanway v. Wyeth Canada Inc., [2012] B.C.J. No. 1198 (C.A.)
  • Bellan v. Fillmore Riley LLP, [2012] M.J. No. 311 (C.A.)
  • Schroeder v. DJO Canada Inc., [2010] S.J. No. 220 (Q.B.)
  • Sifneos c. Pfizer Inc., 2012 QCCS 5772


  • University of Toronto Law School, 1996

Bar Memberships

  • Ontario, 1998

Work Experience

  • Lawyer at Klein Lawyers, 2002-present

Professional Affiliations

  • Law Society of Upper Canada
  • The American Association for Justice.


  • Speaker at 15th National Symposium on Class Actions, Osgoode Hall Law School, May 28-29, 2018
  • “Class Actions as a Source of Funding For Consumer Groups”, Consumers 150 Conference, Ottawa, September 2017
  • “A History of Medical Products Litigation in Canada”, American Association for Justice, Annual Conference, Montreal, July 2015
  • “Why Medical Product Cases are the Most Challenging of Class Actions”, Ontario Bar Association Class Action Colloquium, Toronto, December 2014
  • “New Developments in British Columbia and their Potential Application in Quebec”, Barreau du Quebec Class Action Seminar, March 2013
  • “Expert Evidence at Class Certification: How Much is Necessary and How Much is Overkill?”, Canada Bar Association Class Action Colloquium, December 2012
  • “B.C. and Ontario Class Actions Survey: Common Themes and Differing Approaches”, Canadian Institute National Forum on Class Action Litigation, September 2008
  • “Defeating Class Actions Prior to Certification: A Plaintiff’s Perspective”, co-authored with David Klein, Canadian Institute National Forum on Class action Litigation, September 2007
  • “National and Multi-jurisdictional Domestic Class Actions: How are the Battles Shaking Out?”, Canadian Institute National Forum on Class Action Litigation,  September 2006
  •  “The Nuts and Bolts of a Pharma Class Action”, Canadian Institute National Forum on Class Action Litigation, September 2005
  • “Knowing it when you see it: Class action case selection”, co-authored with David Klein, Continuing Legal Education Society of British Columbia, February 2005
  • “Continental Divide: Emerging Differences between British Columbia and Ontario Class Actions”, co-authored with David Klein, Canadian Institute National Forum on Class Action Litigation, September 2004
  • “Building a Class”, Advocates Quarterly, Vol. 24(4) 2001