Walter Norman Pahnke (Jan 18, 1931 – July 10, 1971) was a minister, physician, and psychiatrist most famous for the "Good Friday Experiment", also referred to as the Marsh Chapel Experiment or the "Miracle of Marsh Chapel".
Pahnke attended Harvard in the early 1960s. He earned an MD from Harvard Medical School, a BD (now M.Div.) from Harvard Divinity School, a Ph.D. from Harvard Graduate School of Arts and Sciences, and a Harvard psychiatric residency. He was a psychedelic researcher at Harvard University.
In 1967, Pahnke joined the Maryland Psychiatric Research Center in Spring Grove, Maryland. He conducted psychedelic therapy sessions using lysergic acid diethylamide and dipropyltryptamine, with terminal cancer patients as well as people suffering from alcoholism and severe neurosis. There he worked with therapists Stanislav Grof, Bill Richards, and Richard Yensen, among others. Pahnke served as director of the project from 1967 until 1971, when he died in a scuba diving accident in Maine.