The profound tragedy into which Stanley Kunitz was born, and the many other personal tragedies that followed, informed and imbued his poetry. He was born in Worcester, Massachusetts, the son of Solomon Z. Kunitz. The elder Kunitz was a prosperous businessman, involved in dress manufacturing. Just a few weeks before Stanley Kunitz was born, his father committed suicide. His mother, grief-stricken and shocked, quickly learned that the family business was bankrupt.

Embarrassed, betrayed, and suffering from the great loss, his mother, Yetta Helen Jasspon (who emigrated from Lithuania), retreated inward, refusing to ever discuss her husband again. She opened a dry-goods store to support her family. When her son was fourteen, his stepfather, Mark Dine, died. Then his sisters married, but they both died young. The theme of loss, particularly that of a father, flows through Kunitz's work like a dark river.

He completed high school at worcester Classical. It was there that poetry captured his imagination. He was particularly fond of English early modern poet, Robert Herrick. He also was informed by John Keats, Alfred Tennyson, William Wordsworth, and William Blake. Blake was known for his visions of heavenly creatures. Kunitz shares the interest in visions, though his are, as were some of Blake's, internal visions. "Poetry emerges out of the mystery and secrecy of being," he has stated.

Kunitz was the recipient of a scholarship to study at Harvard University, where he graduated summa cum laude in 1926. He was then twenty-two years old. He had expressed an interest in undertaking an assistant's position at the university, but was told that his Jewish heritage would prevent that. He then took employment as a newspaper reporter, editor, and even tried his hand at small farming. He also traveled to Europe during this period. Additionally, he began to write and submit poems to such magazines as Poetry, The Dial, The Nation, The New Republic, and Commonweal. His first collection of poems was entitled Intellectual Things, published in 1930.

His romantic, metaphysical style was out of fashion at the time and he did not publish again for fourteen years. During that time he worked as an editor for the H.W. Wilson Company, a series of biographical reference books about authors, which is still published and held in high regard today. When he published again, in 1944, the new volume contained one of his most famous poems, "Father and Son."

During World War II Kunitz was a conscientious objector, but he still served in the army, remaining stateside and editing an Army news magazine. After the war he was the recipient of a Guggenheim grant, which allowed him to live and write in Sante Fe, New Mexico for one year. He then began his teaching career, at Bennington College. He went on to a distinguished academic career, teaching at Yale, Princeton, Rutgers, the New School, and Columbia University. He continued to travel the world, including to Moscow and Tbilisi. He began to translate the work of Russian poets, including Anna Akhmatova and Osip Mandelstam.

Kunitz was awarded a number of literary prizes, including the Pulitzer, the Bollingen Prize, a National Endowment for the Arts Senior Fellowship, and the Ford Foundation Award. In 1993 he was honored with the National Medal of the Arts. During the 1980s he served as the first State Poet of New York. He also gave back to the literary and artistic community when, in 1968, he founded the Fine Arts Work Center, in Provincetown, and was a co-founder of the Poets House on Spring Street in SoHo, New York.