The university recognized her as a “strategic leader in judicial administration with extensive experience in governance, judicial ethics, and codes of conduct. With more than twenty-two years on the bench, she is widely recognized as an expert in criminal law and an innovator in court modernization, with a proven track record of organizational leadership.”
Called to the Bar in 1991, Justice Maisonneuve was a partner with the Ottawa firm of Carroll, Wallace and Maisonneuve, where she practiced criminal law.
She has also served in numerous advisory roles, including as counsel to the Canadian Armed Forces Special Advisory Group on Military Justice and Military Police Investigation Services, headed by the late Chief Justice of Canada, Brian Dickson, and as an advisor to several Department of National Defence initiatives, including oversight and reform committees. She has further contributed as a special advisor to both the Military Police Services Review Group and the Thomas Review Group.
Justice Maisonneuve was appointed to the Ontario Court of Justice in 2003 and presided over criminal matters in the Ottawa area for 12 years and she was appointed Regional Senior Judge for the East Region in 2011.
She served as Chief Justice of the Ontario Court of Justice from 2015 to 2023 and was the first Chief Justice born and raised in Northern Ontario and the first Francophone to be appointed to that position.
Justice Maisonneuve led the Ontario Court of Justice through the unprecedented times of the pandemic which ultimately resulted in a more modern, efficient and accessible court system for Ontarians.
In May 2024, she was appointed Commissioner of the Future of Sport in Canada Commission, for which she delivered her final report in March 2026. The report, the first of its kind in Canada, includes ninety-eight calls to action addressing the future of the national sport system, with a particular focus on strengthening safe sport.
In 2024, the Law Society of Ontario (LSO) bestowed a degree of Doctor of Laws, honoris causa (LLD) on Maisonneuve “whose intellect, sound judgment and understanding of the law and justice system have earned her the respect of the legal professions, the judiciary and Ontarians”
Throughout her term as Chief Justice, the LSO noted, she was committed to working with partners to address systemic challenges in modernizing the criminal justice system, reducing delays and improving access to justice for French-speaking Ontarians.