Sidney N. Lederman served as a judge of the Superior Court of Justice for Ontario for 24 years, during which time he presided primarily over cases on the Commercial List and in Divisional Court branches of the court.
Prior to his appointment to the Bench, he was a senior partner and head of the litigation department at Stikeman Elliott with an emphasis on corporate and securities litigation.
He is the co-author of The Law of Evidence in Civil Cases and the leading text, The Law of Evidence in Canada (5th ed., 2018) which is authoritatively cited by courts and arbitrators.
He has had experience in court mediation while on the Bench, and arbitrations having formerly served as a labour arbitrator and on arbitration panels in international disputes under the auspices of the American Arbitration Association.
As an educator, Sidney Lederman was a professor at Osgoode Hall Law School and was one of the founders of the Canadian Institute for the Administration of Justice. In that capacity, he developed and conducted education programs for the judiciary in Canada and the Commonwealth.
He was the first President of the Canadian Human Rights Tribunal.
Sidney Lederman is an Honourary Director of the Canadian Institute for the Administration of Justice and from 1991 to 2019 was a Fellow of the American College of Trial Lawyers.