Skip to content.
This is a photo of Leah Ostler




Contact by email at [email protected]

t. +1 416-601-8285


Leah is an associate in our Litigation Group in Toronto. Her practice focuses on defence litigation, including commercial matters (specializing in telecommunications, accounting and pensions matters) and professional negligence. She has served as counsel in motions, applications, trials and class actions, and as lead counsel before courts and administrative tribunals in a wide range of complex matters.

Leah’s notable engagements include:

  • Representing the Toronto-Dominion Bank in a timely and novel interpleader application;
  • Representing Bell Canada in a hotly contested injunction with another telecommunications company, which included a parallel regulatory application;
  • Financial institutions in multi-million dollar securities class actions;
  • Professional accounting firms in civil and regulatory proceedings;
  • A university in a complex construction negligence matter;
  • Public corporations in pension class actions, including a complex class action and parallel regulatory proceeding for Brewers Retail Inc., where we were successful before the regulatory tribunal, Superior Court and Court of Appeal;
  • Physicians in liability cases tried before judges and juries, and regulatory proceedings before the CPSO and HPARB;
  • Carroccia v. Ayow, October 2020: Second chair in the successful defence of a physician in a medical negligence jury trial – the first civil jury trial conducted in Ontario under COVID-19 protocols; and
  • McKitty v Hayani, 2019 ONCA 805: Second chair in the successful defence and response to appeal in the leading Canadian case on the legal definition of death.

Leah obtained her Certificate in Pensions Law through the Osgoode Professional Development Office in 2023. Leah is a member of the Pensions & Benefits Section of the Ontario Bar Association and the Ontario Regional Council of the Canadian Pension and Benefits Institute. She recently presented about legal and governance insights at McCarthy Tétrault’s 12th Annual Pension & Benefits Seminar.

Leah received her J.D. from Osgoode Hall Law School, where she held executive positions with the Osgoode Women’s Network (OWN), was a Dean’s Fellow for Torts Law, and led several mentorship programs. Leah did a semester abroad at Amsterdam University, where she took Masters of Laws courses in International Law. Leah obtained her B.A. (Honours) in History and Global Development from Western University and was later a Political Intern for the Department of Foreign Affairs and International Trade (DFAIT) in Ramallah, West Bank.