"Turn on, tune in, drop out" is a counterculture phrase coined by Timothy Leary in the 1960s. This phrase urged hippies to change society by dropping out of it. The phrase was derided by conservative critics.

Turn on, tune in, drop out is also the title of a book (ISBN: 1579510094) of essays by Timothy Leary, covering topics ranging from religion, education and politics to Aldous Huxley, neurology and psychedelic drugs.