Martin Dannecker (born 1942 in Oberndorf am Neckar) is a German sexologist and author. Dannecker was born in Oberndorf am Neckar. After his schooling, he initially entered industrial retailing and later trained as an actor at a theater school in Stuttgart. During this time, Dannecker came out and started to read literature on homosexuality. In 1966, Dannecker moved to Frankfurt am Main, and he enrolled at the university with a focus on philosophy, sociology, and psychology. In 1974, he and psychoanalyst Reimut Reiche published Der gewöhnliche Homosexuelle, a wide-ranging empirical study of German homosexuals.