Leo Eitinger (12 December 1912 – 15 October 1996) was a Norwegian psychiatrist, author and educator. He was a Holocaust survivor who studied the late-onset psychological trauma experienced by people who went through separation and psychological pain early in life only to show traumatic experience decades later. He devoted a long period studying posttraumatic stress disorder among Holocaust survivors, which had led Holocaust survivors including Paul Celan (1920– 1970), Primo Levi (1919–1987) and many others to commit suicide several decades after the experience. Eitinger was a pioneer of research into psychological trauma among refugees, and also laid the foundation for Norwegian military psychiatry research with emphasis on psychological trauma among soldiers.