Flower power was a slogan used during the late 1960s and early 1970s as a symbol of passive resistance and nonviolence. It is rooted in the opposition movement to the Vietnam War. The expression was coined by the American Beat poet Allen Ginsberg in 1965 as a means to transform war protests into peaceful affirmative spectacles. Hippies embraced the symbolism by dressing in clothing with embroidered flowers and vibrant colors, wearing flowers in their hair, and distributing flowers to the public, becoming known as flower children. The term later became generalized as a modern reference to the hippie movement and the so-called counterculture of drugs, psychedelic music, psychedelic art and social permissiveness.

Flower child originated as a synonym for hippie, especially among the idealistic young people who gathered in San Francisco and the surrounding area during the Summer of Love in 1967. It was the custom of "flower children" to wear and distribute flowers or floral-themed decorations to symbolize ideals of universal belonging, peace, and love. The mass media picked up on the term and used it to refer in a broad sense to any hippie. Flower children were also associated with the flower power political movement, which originated in ideas written by Allen Ginsberg in 1965.