The Honourable Mary T. Moreau earned her Bachelor of Laws from the University of Alberta in 1979. She was called to the Alberta Bar in 1980. Her legal practice focused primarily on criminal, constitutional, and civil litigation. She appeared as counsel in several landmark cases involving minority official language rights and was a co-founder of the Association des juristes d’expression française de l’Alberta.

In 1994, she was appointed to the Court of King’s Bench of Alberta. She later served as a deputy justice of the Supreme Court of Yukon and the Supreme Court of the Northwest Territories. In 2017, she was appointed as Chief Justice of the Court of King’s Bench of Alberta. Throughout her judicial career, Justice Moreau has been engaged in judicial education, ethics, and administration, including judicial education and support initiatives in Mexico, Morocco, Haiti, Ukraine, and Mongolia. She served as President of the Canadian Superior Courts Judges Association from 2011 to 2012.

In recognition of her contributions to the legal profession, she received an honorary Doctorate from the University of Alberta in 2019 and a Lifetime Achievement Award from Women in Law Leadership in November 2023.

Justice Moreau was appointed to the Supreme Court of Canada in November 2023