John Michael Wallace (born October 28, 1940), is a professor of Atmospheric Sciences at the University of Washington, as well as the former director of the Joint Institute for the Study of the Atmosphere and Ocean (JISAO)—a joint research venture between the University of Washington and the National Oceanic and Atmospheric Administration (NOAA). His research concerns understanding global climate and its variations using observations and covers the quasi biennial oscillation, Pacific decadal oscillation and the annular modes of the Arctic oscillation and the Antarctic oscillation, and the dominant spatial patterns in month-to-month and year-to-year climate variability, including the one through which El Niño phenomenon in the tropical Pacific influences climate over North America. He is also the coauthor with Peter V. Hobbs of what is generally considered the standard introductory textbook in the field: Atmospheric Science: An Introductory Survey. He was the third most cited geoscientist during the period 1973–2007.