Michelle O'Bonsawin

Early legal career O'Bonsawin began her legal career working for Royal Canadian Mounted Police legal services. O'Bonsawin worked as in-house counsel for Canada Post for nine years before she joined the Royal Ottawa Health Care Group in 2009. There she worked as general counsel and established its legal services department. She also appeared as counsel for the organization on mental-health cases before the Ontario Superior Court and Ontario Court of Appeal as well as tribunals such as Ontario's Consent and Capacity Board and the Ontario Review Board.

While working, she also studied to earn a master's degree in law from Osgoode Hall Law School. Her practice focused on mental health, labour and employment, human rights, and privacy. She also taught a course on Indigenous peoples and the law at the University of Ottawa Faculty of Law. She assumed office on May 18, 2017. In her application for the position, she described her legal philosophy as "progressive". Her PhD thesis has been embargoed and is not available for public consultation, which has raised concerns and attracted criticism.

In 2017, O'Bonsawin was the trial judge for the case CM Callow Inc v Zollinger, which applied the general organizing principle of good faith contractual performance from the 2014 Supreme Court of Canada case Bhasin v Hrynew. In 2018, the Court of Appeal for Ontario overturned her decision, ruling that she had improperly expanded the duty in a manner not directly linked to the performance of the contract and limited an expressly bargained-for right. In 2020, a majority of the Supreme Court of Canada overruled the Ontario Court of Appeal, reinstated O'Bonsawin's trial award, and provided clarity on the application of Bhasin.

In 2024, the National Post reported that at least two of O'Bonsawin's decisions on the Superior Court of Justice have been reversed by the Ontario Court of Appeal.

In summer 2021, she co-chaired a conference organized by an association for French-speaking judges in Ontario.

Supreme Court of Canada On August 19, 2022, Prime Minister Justin Trudeau nominated O'Bonsawin to the Supreme Court of Canada to replace retiring Justice Michael Moldaver. On August 24, O'Bonsawin appeared for a special meeting with the Standing Committee on Justice and Human Rights to answer questions from parliamentarians from both the House of Commons and Senate. O'Bonsawin is the first Indigenous person to sit on Canada's highest court.

Personal life O'Bonsawin is Franco-Ontarian and fluently bilingual, and as of May 2022, was taking lessons in the Abenaki language. She is married with two sons.