Darin W. Toohey is an American atmospheric scientist. He has been a professor of atmospheric and oceanic sciences and of environmental studies at the University of Colorado Boulder since 1999. He received a B.S. in chemistry and a B.A. in physics at California State University, Fullerton in 1982 and a Ph.D. in applied physics at Harvard University in 1988. Toohey's research addresses the role of trace gases and aerosols on Earth's climate, atmospheric oxidation, and air quality.