Peter Gray may refer to: Peter Gray (historian) (born 1965), professor of modern Irish history at Queen's University Belfast Peter Gray (chemist) (1926–2012), professor of physical chemistry at the University of Leeds Peter Gray (Australian judge), Federal Court of Australia judge Peter Gray (military historian), military historian at Birmingham University Peter Gray (psychologist) (born 1944), American psychologist and author of the introductory psychology textbook, Psychology "Peter Gray" (song), American ballad Peter Gray (writer) (1807–1887), Scottish writer Peter S. Gray (born 1957), Olympic equestrian for Bermuda and Canada Peter W. Gray (1819–1874), American lawyer, judge, and legislator from Texas Peter Gray (bioengineer) (born 1946), bioengineer in Australia Pete Gray (1915–2002), one-armed Major League baseball player Pete Gray (activist) (1980–2011), Australian environmental and anti-war activist