Michael Oppenheimer (born February 28, 1946) is the Albert G. Milbank Professor of Geosciences and International Affairs in the Princeton School of Public and International Affairs, the Department of Geosciences, and the High Meadows Environmental Institute at Princeton University. He is the director of the Center for Policy Research on Energy and the Environment (C-PREE) at the Princeton School of Public and International Affairs and Faculty Associate of the Atmospheric and Ocean Sciences Program and the Princeton Institute for International and Regional Studies.

Oppenheimer has played a leading role at the interface of science and public policy including influencing the development of the acid rain provisions of the US Clean Air Act. He co-organized a series of activities that prefigured the emergence of climate change as a top international concern and influenced the development of the United Nations Framework Convention on Climate Change. He directed climate and air pollution activities at the Environmental Defense Fund when that NGO's science-based and incentive-based approach to climate change was reflected in the language of the Kyoto Protocol. Oppenheimer has played a significant role within the Nobel Prize-winning Intergovernmental Panel on Climate Change (IPCC), serving as Contributing Author, Lead Author, or Coordinating Lead Author on each assessment report since IPCC's first report, as well as two special reports. Oppenheimer also serves as a Review Editor on the Sixth Assessment Report.