The Interpretation of Dreams (German: Die Traumdeutung) is an 1899 book by Sigmund Freud, the founder of psychoanalysis, in which the author introduces his theory of the unconscious with respect to dream interpretation, and discusses what would later become the theory of the Oedipus complex. Freud revised the book at least eight times and, in the third edition, added an extensive section which treated dream symbolism very literally, following the influence of Wilhelm Stekel. Freud said of this work, "Insight such as this falls to one's lot but once in a lifetime."

Sigmund Freud was an Austrian neurologist and the founder of psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst. In founding psychoanalysis, Freud developed therapeutic techniques such as the use of free association and discovered transference, establishing its central role in the analytic process.