Mark Kenneth Jaccard (born April 12, 1955) is a Canadian energy economist and author.

He develops and applies models that assess sustainability policies for energy and material.

Jaccard is a professor of sustainable energy in the School of Resource and Environmental Management (REM) at Simon Fraser University.

His research focuses on the development and application of energy-economy-emissions models that simulate the likely effects of sustainable energy policies.

Utilities Commission (1992 to 1997), on the Intergovernmental Panel on Climate Change (1993–96, 2008–09), and on the China Council for International Cooperation on Environment and Development (1996-2001, 2008–09).