W. Gary Ernst (born December 14, 1931) is an American geologist specializing in petrology and geochemistry.
He currently is the Benjamin M. Page Professor Emeritus in Stanford University's department of geological sciences.
From 1960 to 1989, he was a professor in the Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics at UCLA, where he also served terms as chair of the Department of Geology, chair of the Department of Earth and Space Sciences, and director of the Institute of Geophysics and Planetary Physics.
Ernst's research interests have included the petrology, geochemistry, and plate tectonics of Circumpacific and Alpine mobile belts, ultrahigh-pressure metamorphism in Eurasia, geology of the California Coast Ranges, the central Klamath Mountains, and White-Inyo Range, geobotany and remote sensing of the southwestern United States; and mineralogy and human health.
He was the 2004 recipient of the Penrose Medal of the Geological Society of America,[3] 2006 recipient of the Roebling Medal of the Mineralogical Society of America,[4][5] and 2008 recipient of the Marcus Milling Legendary Geoscientist Medal.