Our Team
Leslie Dizgun

Leslie Dizgun conducts a sophisticated commercial litigation and employment law practice.  Mr. Dizgun is often retained by other employment law lawyers and family law lawyers on commercial litigation issues arising in their practice areas.

In addition to his litigation practice, Mr. Dizgun is a well respected mediator and arbitrator of commercial and employment disputes. He is a member of the ADR Chambers expert panels. The ADR Chambers is the largest alternative dispute resolution service provider in the world. Mr. Dizgun has been very successful in resolving difficult and complex proceedings.

Mr. Dizgun has a Master of Laws degree in Alternative Dispute Resolution from  Osgoode Hall Law School, where he is also an adjunct professor. He has taught Civil Procedure, the Senior Colloquium in Dispute Resolution and the Administration of Justice, and continues to teach Dispute Settlement in the Civil Justice System.

Mr. Dizgun is committed to standards of excellence in advocacy and dispute resolution.  He is often asked to teach and instruct other lawyers in continuing education programs. He was recently honoured by the Advocates Society, the premier advocacy organization for litigation lawyers, with the award for teaching excellence, for his contributions to the continuing legal education of lawyers in Ontario.

Mr. Dizgun brings a sophisticated and nuanced approach to representing clients, and has the skills and experience to achieve excellent results in an efficient and cost effective fashion.


Leslie Dizgun is an experienced advocate in civil litigation and employment law. Mr. Dizgun has a sophisticated corporate/commercial litigation and employment law practice. In addition to his litigation practice in civil litigation and employment law, Mr. Dizgun is an experienced mediator, a Chartered Mediator, and is an adjunct professor at Osgoode Hall Law School, York University, Toronto, where he has taught Civil Procedure, and the Capstone Colloquium in Litigation, Dispute Resolution, and Administration of Justice, and now teaches Dispute Settlement in the Civil Justice System.


  • 29 years’ experience in dispute resolution before all levels of the Ontario Courts.
  • Acted as counsel to a public company in the resolution of the first employment law class action in the Province of Ontario, including the systematic resolution of over eighty wrongful dismissal claims by way of negotiation, mediation and arbitration.
  • Acted as counsel in a precedent setting pay equity case before the Pay Equity Hearings Tribunal.
  • Acted as counsel to national elevator company in largest Fatality Inquiry in the Province of Alberta, investigating elevator related fatality.
  • Acted for vendor of $2 million Lake Joseph property in a complex claim by Wayne Gretsky to ownership of the cottage, and succeeded on motion for summary judgment
  • Acted for commercial landlord of long term lease at 1960’s lease rates, and lease terminated for failure to obtain landlord’s consent to sub-lease, by Court of Appeal
  • Acted successfully for purchaser of Molson plant in Barrie, against owner, in series of applications, including an appeal to the Court of Appeal, pursuant to Proceeds of Crime legislation, to prevent the purchase from the institutional mortgagee;
  • Appeared as counsel in the Superior Court of Justice, Divisional Court and Ontario Court of Appeal in a variety of cases.
  • Panelist – The Outlook for Mediation:Entering the New Mandate of the Ontario Mandatory Mediation Program, Arbitration and Mediation Institute of Ontario. Monday, May 28, 2001.
  • “Mediation Advocay”, in Mediation and Negotiation: Representing Clients, ed. Michael Silver, 2001.
  • “Med-Arb: Crossing The Line”, in A Practitioner’s Guide To Commercial Arbitration, ed. M. Huberman, 2017.
  • Co-author of text, Mediation Advocacy: Effective Client Representation.
  • Panel Member, LSUC Employment Law Summit, 2013, “The Psychological Aspects of Negotiation”
  • Co-chair, Civil Motions Workshop, Advocates Society, repeated program
  • Panel Member, OBA ADR section presentation: Why Mediations Fail, January, 2011
  • Co-chair, Mediation Advocacy Workshop, Advocates Society, 2010, 2017, presented in Toronto, London, Ottawa, Barrie, and St. John’s , Newfoundland.
  • Co-Chair, Advanced Mediation Advocacy Workshop, Advocates Society, 2017.
  • Co-chair, ADR Workshop: Creative and Efficient Use of ADR in Franchising, 2012 OBA Franchise Law Conference
  • Co-chair, Arbitration Workshop: Does A Decision To Arbitrate Still Make Sense, 2011 OBA Franchise Law Conference.
  • Employment Law Summit 2010, Presentation: Torts in the Workplace after Piresferreira and Bill 168, LSUC, October 28, 2010.
  • Canadian Institute: 6th Annual Advanced Forum on Employment Law – Presentation: The Elusive [Un]Certainties of Employment Law. October 18th and 19th, 2006.
  • Member (instructor) of Faculty, Advocates Society of Ontario. Workshop instructor in Evidence, Cross-Examination, Motions Advocacy, and Trial Advocacy.
  • Workshop leader; A.D.R. and Advanced Mediation, Kroll, Lindquist, Avey National Conference, April, 2000.
  • Panel Member: Mandatory Mediation Best Practices. Arbitration and Mediation Institute of Ontario Annual General Meeting; May, 2000.
  • Co-Chair of conference on Alternative Dispute Resolution: Strategies to Resolve Workplace Conflict and Focus on Corporate Productivity, May 27 and May 28, 1999.
  • Co-Chair, LSUC, February 1999, Civil Motions Workshop.
  • Training Superior Court Judges in effective Settlement Conference Practices, National Judicial Institute, November/December 1999, and Advanced Effective Settlement Conferences, December 2000.
  • Co-Chair of the Advocates’ Society / Law Society of Upper Canada Civil Motions Workshop, 1999, 2002, 2003, 2004, 2006, 2008, 2010.
  • Training Ontario Government lawyers on behalf of the Office of the Attorney General in Mediation Advocacy.
  • Training Workshops in Mediation Advocacy for Torkin, Manes, Cohen & Arbus, Weir & Foulds, McCarthy, Tetrault,Blake, Cassels, and Gowlings WLG.
  • Panel Member, January 1999 - The Ministry of the Attorney General’s Orientation of Mandatory Mediation Roster Mediators.
  • Osgoode Hall Law School of York University, Professional Development Programme, November 3 & 4, 1998, Mandatory Mediation. Presentation: Choosing the Mediator - From the Roster; From Off the Roster.Crossing The Line
  • Insight Information Inc., June 19, 1998, Mandatory Mediation. Presentation: The Nuts and Bolts: A Walk Through the Rules.
  • Presentation and paper on Mediation Advocacy. LSUC, February 10, 1998, Resolving Commercial Disputes. Presentation and Paper: Managing Multiple Claims: Expanding the ADR Arena.
  • Presentation, CBAO Annual Institute, January 30, 1998, ADR Section Programme. Presentation and Paper: Mediation Advocacy.
  • Faculty, Civil Motions Workshop, The Law Society of Upper Canada, April, 1997.
  • Faculty, Counsel in a Mediation, Ontario Centre for Advocacy Training, April, 1997.
  • Workshop Co-Leader, Conducting a Disciplinary Hearing and Writing Effective Reasons, Conference, Professional, Misconduct in the Health Care Sector, March, 1997, Infonex Conferences.
  • Panel Member, CBAO Seminar. Mediating in a Mandatory Regime. 1997.
  • Intensive Workshop Leader Psychotherapy and the Law, Workshop, October, 1996, Leading Edge Seminars
  • “Confidentiality of Client/Patient Records”, Psychotherapy and the Law, Conference, December 8, 1995, Leading Edge Seminars.
  • Individual Rights and Social Housing. Presentation at Canadian Mental Health Association Annual General Meeting and Workshop: Housing and Support for Consumers/Survivors: Untying the Knot (Friday, June 9, 1995).
  • Panel Member on Sexual Harassment in the Workplace - Addiction Intervention Association Convention 1993.
  • Bill of Rights and Charter Challenges to Special Limitation Periods, in “Avoiding the Expiry of Limitation Periods”. The Honourable Patrick Thomas Galligan and L. Leslie Dizgun: CBAO Annual Institute, March, 1989.
  • The Role of the Charter in Grievance Arbitration. J.C. Murray and L. Leslie Dizgun: Canada Labour Views Conference, April 20, 1988.
  • Directors’ duties and liabilities of non-profit organizations. Presentation to Syme Family Centre.

Master of Arts, Concordia University, 1984.

Bachelor of Laws, Osgoode Hall Law School, York University, 1986.

Certified Mediation Workshop, Harvard Law School, 1995.

Master of Laws in Alternative Dispute Resolution, Osgoode Hall Law School, York University, 1997.

Chartered Mediator, ADR Institute of Canada, (as of) 2010.

Member, CBAO, ADR, Civil Litigation, Labour sections.

Member, CBAO, Code of Conduct subsection, ADR Section.

Member, Advocates Society Faculty, CLE programming

Member, Advisory Council to the Pay Equity Commission.

Member, Transitional Physician Audit Panel of the Health Services Appeal and Review Board (2003- 2006).

Vice-Chair, Health Services Appeal and Review Board (2006-2009)

Board member, Osgoode Hall Alumni Association (2004-2010)

Adjunct Professor, Osgoode Hall Law School (current)