A Canadian national, Louise Arbour, began her academic career in 1974 at Osgoode Hall Law School of York University in Toronto. In December 1987, she was appointed to the Supreme Court of Ontario, and in 1990, she was appointed to the Court of Appeal for Ontario. In 1995, as Commissioner of an inquiry into the Prison for Women in Kingston, Ontario, she produced a report which accelerated the move to modernize institutions that were specifically designed to meet the security and programming needs of women inmates.

In 1996, the United Nations Security Council appointed Arbour as Chief Prosecutor of the International Criminal Tribunals for the former Yugoslavia and Rwanda. In this role, she secured the first conviction for genocide (Rwanda) since the 1948 Genocide Convention and the first indictment for war crimes by a sitting European head of state (Serbian President Slobodan Milosevic). After three years as Prosecutor, she resigned to take up an appointment to the Supreme Court of Canada.

She was appointed High Commissioner for Human Rights at the United Nations (2004-2008), and the UN Special Representative of the Secretary-General on International Migration (2017-2018). Arbour, Senior Counsel at Borden Ladner Gervais LLP, was appointed in 2021 to lead an independent review into sexual misconduct in the Canadian Armed Forces.

Arbour has received numerous honorary doctorates and awards. She is a Companion of the Order of Canada, a Grand Officer of the Ordre national du Québec, and a Commander of the Ordre de Montréal.

She joined the Global Commission on Drug Policy in 2011 and serves as a current member of its Steering Committee.