Born on Leap Day in New York City, his parents were David Nemerov and Gertrude. The Nemerovs were a Russian Jewish couple who lived in New York City and owned Russek's, a famous Fifth Avenue department store. His younger sister was the photographer Diane Arbus. The elder Nemerov's talents and interests extended to art connoisseurship, painting, philanthropy, and photography — talents and interests undoubtedly influential upon his son. Young Howard was raised in a sophisticated New York City environment where he attended the Society for Ethical Culture's Fieldston School. Graduated in 1937 as an outstanding student and second string team football fullback, he commenced studies at Harvard University where, in 1940, he was Bowdoin Essayist and he received bachelor's degree at this university. Throughout World War II, he served as a pilot, first in the Royal Canadian Air Force and later the U. S. Army Air Forces. He married in 1944, and after the war, having earned the rank of first lieutenant, returned to New York with his wife to complete his first book.
Nemerov then began teaching, first at Hamilton College and later at Bennington College, Brandeis University, and finally Washington University in St. Louis, where he was Edward Mallinckrodt Distinguished University Professor of English and Distinguished Poet in Residence from 1969 until his death in 1991. In 1999, Washington University dedicated a dormitory, The Howard Nemerov House, to him. Nemerov's numerous collections of poetry include Trying Conclusions: New and Selected Poems, 1961-1991 (University of Chicago Press, 1991); The Collected Poems of Howard Nemerov (1977), which won the Pulitzer Prize, the National Book Award, and the Bollingen Prize; The Winter Lightning: Selected Poems (1968); Mirrors and Windows (1958); The Salt Garden (1955); and The Image of the Law (1947). His novels have also been commended; they include The Homecoming Game (1957), Federigo: Or the Power of Love (1954), and The Melodramatists (1949).
Nemerov received many awards and honors, among them fellowships from The Academy of American Poets and The Guggenheim Foundation, a National Endowment for the Arts grant, the National Medal of Arts, the Bollingen Prize for Poetry, and the first Aiken Taylor Award for Modern American Poetry.
Nemerov served as poetry consultant to the Library of Congress in 1963 and 1964, as a Chancellor of the Academy of American Poets beginning in 1976, and two terms as poet laureate of the United States from 1988 to 1990. In 1990 he was inducted into the St. Louis Walk of Fame. Nemerov died of cancer in 1991 in University City, Missouri. The Howard Nemerov Sonnet Award was instituted in 1994 to honor him, and by 2008 about 3000 sonnets were entered annually in the associated competition.