James Ingram Merrill was born on 3 March 1926 in New York City to Charles E. Merrill, founding partner of the Merrill Lynch investment firm. Merrill's nanny taught him French and German.
His parents divorced when he was twelve years old. He attended the Lawrenceville School. In his senior year Merrill's father collected his short stories and poems and published them under the name Jim's Book.
Merrill served two years in the United States Army during World War II. After the war he attended Amherst College and graduated in 1947.
Merrill's partner was David Jackson, a writer and musician. Merrill and Jackson moved to Stonington, Connecticut in 1955. They also spent a great deal of time in Greece. In 1979 Merrill and Jackson spent summers at Jackson's home in Key West, Florida.
Merrill published his first adult book, First Poems, in 1951. In 1977 Merrill won the Pulitzer Prize for Poetry for Divine Comedies. Merrill suffered writer's block and sought psychiatric help to overcome its effects.
Merrill won the National Book Critics Circle Award for his epic poem The Changing Light at Sandover (composed partly of supposedly supernatural messages received via ouija board), and the first Bobbitt National Prize for Poetry awarded by the Library of Congress for The Inner Room. He won National Book Awards for Nights and Days and later for Mirabell.
James Merrill's significance as a writer lies in his deliberate use of his personal relationships to fuel his poetry.
He died on 6 February 1995 while vacationing in Arizona from a heart attack related to AIDS.
He served as a Chancellor of the Academy of American Poets from 1979 until his death.