Ivan Leigh Head OC QC (July 28, 1930 – November 1, 2004) was a Canadian lawyer, legal scholar, and civil servant.
He was an influential foreign policy adviser of Prime Minister Pierre Trudeau.
From 1960 to 1963, he was a foreign service officer with the Department of External Affairs working in Ottawa, Ontario, and Kuala Lumpur, Malaysia.
In 1991, he was appointed a professor of law at the University of British Columbia and was the founding director of UBC's Liu Institute for Global Issues.
He co-authored with Pierre Trudeau the book The Canadian Way: Shaping Canada’s Foreign Policy 1968–1984 (McClelland & Stewart, 1995, ISBN 0-7710-4099-7) and was the author of On a Hinge of History: The Mutual Vulnerability of South and North (University of Toronto Press, ISBN 0-8020-2766-0).