Jonathan R. Tatner

Senior Counsel

Bar Admissions

  • Ontario, 2013
  • Quebec, 2008


  • Juris Doctor (J.D.) (Common Law), Université de Montréal (2012)
  • Bachelor of Laws (LL.B.) (Civil Law), Université de Montréal (2007)
  • Bachelor of Arts (B.A.) (History and Political Science), McGill University (2004)

Professional Accreditations and Affiliations

  • Barreau du Québec
  • Ontario Bar Association
  • Canadian Bar Association
  • The Advocates’ Society
  • Canadian Defence Lawyers

About Lawyer

Jonathan Tatner is a senior litigation lawyer at the Toronto office, having joined Aviva Trial Lawyers in 2021. Jonathan’s practice focuses on civil litigation in the areas of bodily injury, occupiers’ liability, property damage, commercial liability, and product liability.

Jonathan’s previous experience includes insurance defence litigation in private practice. Jonathan has also practiced civil and commercial litigation in Montreal, handling matters relating to contracts, property, wills and estates, defamation, and intellectual property.

Jonathan has trial, tribunal hearing, and arbitration experience, and he appears before the Courts of Ontario. He is licensed to practice law in both Ontario and Quebec, and he is fluent in both official languages.

Notable Cases

  • Barclay v. Ontario Gymnastics, April 11, 2022 (ON SC, Jury Trial) (Occupiers’ Liability) (The defendant successfully had the claim dismissed)
  • JC v. Western Assurance Company, 2019 CanLII 94031 (ON LAT)
  • 16-003709/AABS v. Unifund Assurance Company, 2018 CanLII 2302 (ON LAT)
  • World Dask Holdings (WDH) Ltd. c. Company Quartermaster Services Ltd., 2011 QCCS 4260 (CanLII)
  • Assaad c. Antonacci, 2010 QCCQ 12862 (CanLII)

Personal Interests

Jonathan is an avid runner (including several marathons) and has a passion for music (playing guitar and piano), tennis, cycling, travel, and quality time with family and friends.