Guenter Lewy (born August 22, 1923) is a German-born American author and political scientist who is a professor emeritus of Political Science at the University of Massachusetts Amherst. His works span several topics, but he is most often associated with his 1978 book on the Vietnam War, America in Vietnam, and several controversial works that deal with the applicability of the term genocide to various historical events.
In 1939 he migrated from Germany to Mandatory Palestine. After World War II, he migrated to the United States to reunite with his parents. Lewy earned a BA at City College in New York City and a MA and PhD at Columbia University. He has been on the faculties of Columbia University, Smith College, and the University of Massachusetts Amherst. He currently lives in Washington, D.C., and is a frequent contributor to Commentary.