Carl Gustav Jung (YUUNG; German: kaʁl ˈjʊŋ), born July 26, 1875, was a Swiss psychiatrist and psychoanalyst who founded analytical psychology. He was a prolific author, illustrator, and correspondent, and a complex and controversial character, presumably best known through his "autobiography" Memories, Dreams, Reflections.

Jung's work has been influential in the fields of psychiatry, anthropology, archaeology, literature, philosophy, psychology, and religious studies. He worked as a research scientist at the Burghölzli psychiatric hospital, in Zurich, under Eugen Bleuler. Jung established himself as an influential mind, developing a friendship with Sigmund Freud, founder of psychoanalysis, conducting a lengthy correspondence paramount to their joint vision of human psychology. Jung is widely regarded as one of the most influential psychologists in history.

Freud saw the younger Jung not only as the heir he had been seeking to take forward his "new science" of psychoanalysis, but as a means to legitimize his own work: Freud and other contemporary psychoanalysts were Jews facing rising antisemitism in Europe, and Jung was Christian. Freud secured Jung's appointment as president of Freud's newly founded International Psychoanalytical Association. Jung's research and personal vision, however, made it difficult to follow his older colleague's doctrine and they parted ways. This division was painful for Jung and resulted in the establishment of Jung's analytical psychology, as a comprehensive system separate from psychoanalysis.

Among the central concepts of analytical psychology is individuation—the lifelong psychological process of differentiation of the self out of each individual's conscious and unconscious elements. Jung considered it to be the main task of human development. He created some of the best known psychological concepts, including synchronicity, archetypal phenomena, the collective unconscious, the psychological complex, and extraversion and introversion. Jung was also an artist, craftsman, builder, and prolific writer. Many of his works were not published until after his death and some remain unpublished.