Meltzer was born in Rochester, New York, the son of a cellist and a harpist. In 1940, the family moved to Brooklyn. At the age of 11, he wrote his first poem, on the topic of the New York City subway system. He performed on radio and TV in "The Horn and Hardart Children's Hour". The family moved once again to Rockville Centre. His parents separated, and he accompanied his father to Los Angeles in 1954. In 1957, he moved to San Francisco and became part of a circle of writers based around Jack Spicer and Robert Duncan.