Ralph Metzner (May 18, 1936 – March 14, 2019) was an American psychologist, and writer. He was born in 1936, in Germany. With Timothy Leary and Richard Alpert he was involved in a series of tests done at Harvard University, in the 1960s. These tests involved psychedelic drugs.
In the 1960s, professors Timothy Leary, Ralph Metzner and Richard Alpert collaborated on a book titled The Psychedelic Experience, which adapted portions of the Tibetan Book of the Dead as a guide for use in LSD experiences. They hoped to give users of LSD a simulation of death and rebirth, to "liberate" them from past problems or mistakes in their lives.