Walter Charles Langer was an American psychoanalyst who prepared a detailed psychological analysis of Adolf Hitler in 1943. Langer studied psychoanalysis at Harvard University, where he worked as a professor upon completion of his education. Langer was later employed by the Office of Strategic Services (OSS), where in 1943 he prepared a psychoanalysis profile of Hitler. In this analysis, Langer accurately predicted that Hitler would commit suicide as the "most plausible outcome", and the possibility of a military coup against Hitler well before the assassination attempt of 1944.

The Mind of Adolf Hitler: The Secret Wartime Report, published in 1972 by Basic Books, is based on a World War II report by psychoanalyst Walter C. Langer which probed the psychology of Adolf Hitler from the available information. The original report was prepared for the United States' Office of Strategic Services (OSS) and submitted in late 1943 or early 1944; it is officially entitled A Psychological Analysis of Adolph Hitler: His Life and Legend. The report is one of two psychoanalytic reports prepared for the OSS during the war in an attempt to assess Hitler's personality; the other is Analysis of the Personality of Adolph Hitler by the psychologist Henry A. Murray who also contributed to Langer's report.