Born and raised in Worcester, Massachusetts, Kunitz was educated at Harvard. Declaring himself a pacifist, he served in the army during World War II cleaning latrines. He taught poetry workshops at several colleges, coedited a number of biographical dictionaries, helped to establish the Provincetown Fine Arts Work Center, edited the Yale Series of Younger Poets (from 1974-1976), and refined an increasingly open, almost conversational poetic voice. A 1967 trip to the Soviet Union led to his translating several poets from the Russian.