Marcia Kemper McNutt (born February 19, 1952) is an American geophysicist and the 22nd president of the National Academy of Sciences (NAS) of the United States.

McNutt was the 15th director of the United States Geological Survey (USGS) (the first woman to hold the post) as well as science adviser to the United States Secretary of the Interior from 2010 to 2013. Before working for USGS, McNutt was president and chief executive officer of the Monterey Bay Aquarium Research Institute (MBARI), an oceanographic research center in the United States, professor of marine geophysics at the Stanford University School of Earth Sciences, professor of marine geophysics at University of California, Santa Cruz, and professor of geophysics at the Massachusetts Institute of Technology.

She served as editor-in-chief of the peer-reviewed journal Science from 2013 to 2016 and holds a visiting appointment at the Scripps Institution of Oceanography. She is a member of the National Academies of Sciences, Engineering, and Medicine advisory committee for the Division on Earth and Life Studies and the Forum on Open Science.

McNutt chaired the NASEM climate intervention committee who delivered two reports in 2015.