David Johnston completed his university studies with honours in three countries: the United States (Harvard, A.B. 1963), the United Kingdom (Cambridge, LL.B 1965) and Canada (Queen's, LL.B. 1966). His academic specializations are securities regulation, corporation and information technology law. While at Harvard he was twice named to the All-American Hockey Team and is a member of the Harvard Athletic Hall of Fame.

David Johnston began his professional career as Assistant Professor in the Faculty of Law at Queen's University (1966), moving to the Law Faculty at the University of Toronto in 1968. He became Dean of the Faculty of Law at the University of Western Ontario in 1974. In 1979, he was named the 14th Principal and Vice-Chancellor of McGill University. In July 1994, he returned to McGill's Faculty of Law as a full-time Professor. In June 1999 he became the 5th President of the University of Waterloo.

Among many honours accorded David Johnston are honourary doctorates from twelve universities and Companion of the Order of Canada. He is the author/co-author of numerous books, including Getting Canada Online: Understanding the Information Highway, which is intended to challenge Canadians to use the information revolution to build a more economically competitive and civic society, also Cyberlaw, Communication Law and most recently Canadian Securities Regulation, 4th edition.

David Johnston has served on many provincial and federal task forces and committees and is on the boards of a number of companies and foundations. He was President of the Association of Universities and Colleges of Canada (1985-87) and of the Conférence de recteurs et des principaux des universitiés du Québec (1985-87). He was the founding chair of the National Round Table on Environment and the Economy (1988-91). More recently he has chaired the Board of Overseers of Harvard University, the Canadian Institute for Advanced Research, the Neuroscience Network Centre of Excellence, the Federal Government's Information Highway Advisory Council, its Blue Ribbon Panel on Smart Communities, the Advisory Committee on Online Learning, the National Broadband Task Force, and the Canadian Information System for the Environment. He is a member of Ontario's Task Force on Competitiveness, Productivity and Economic Progress, and Canada's Sustainable Development Technology Foundation. He currently is a Board member of Masco Corp., CGI, Fairfax Financial and a founding trustee of the MasterCard Foundation.

He and his wife, Dr. Sharon Johnston, have five daughters and live on a farm near the University of Waterloo in Heidelberg, Ontario.