Patricia McMahon

Patricia McMahon is the coordinator and lead interviewer of the Osgoode Society’s Oral History Program. She is a lawyer and historian living in Toronto.

Dr. McMahon holds a Ph.D. in History from the University of Toronto and a J.S.D. from Yale Law School. Her Ph.D. dissertation examined the influence of public opinion on Canada’s nuclear policy under John Diefenbaker and Lester Pearson. Her J.S.D. dissertation detailed how pressure groups influenced the fusion of law and equity culminating in England’s Judicature Acts of 1873-1875.

Called to the Bar of Ontario in 2004, Dr. McMahon worked for a decade as a civil litigator at Osler, Hoskin and Harcourt LLP before joining Torys LLP as a research lawyer. Her practice focuses on civil, constitutional, and tax disputes, and she has appeared before all levels of court. Before joining Osler, Trish served as a law clerk to Mr. Justice Ian Binnie at the Supreme Court of Canada and was a Fulbright Scholar at Yale Law School. While at Yale, she was a student director in a legal aid clinic engaged in civil liberties litigation related to the policies of the US government following the attacks on September 11, 2001. This included cases involving detentions, search and seizure, due process, international human rights, and humanitarian law. From 2004 to 2008, she served as a Regional Representative for the Executive Committee of Yale Law School.

Dr. McMahon was invited to join the Society’s Board of Directors in 2009, a position she held until becoming the Oral History Program Coordinator and lead interviewer in 2016. The Osgoode Society’s oral history collection is the world’s largest oral history collection focused on law, and Trish has been instrumental in democratizing access to the collection and increasing the diversity of interview subjects.  In particular, she has expanded access to the collection’s more than 630 interviews by digitizing all interview transcripts to permit keyword searching of their contents. The Osgoode Society now provides access to electronic copies of open oral history interview transcripts free of charge.

Osgoode Society for Canadian Legal History Books

The Persons Case: The Origin and Legacy of the Fight for Legal Personhood (Toronto: The Osgoode Society and the University of Toronto Press, 2007), 269 pp. (with Mr. Justice Robert Sharpe).

Chapters in Osgoode Society Books

“Conscription and the Courts: The Case of George Edwin Gray, 1918” in Security, Dissent and the Limits of Toleration in War and Peace: Canadian State Trials Volume IV, 1914-1939 (Toronto:  The Osgoode Society and the University of Toronto Press, 2015), Barry Wright, Eric Tucker, and Susan Binnie (eds).