Louis Aston Marantz Simpson (born March 27, 1923 in Jamaica) is a Jamaican poet. He won the 1964 Pulitzer Prize for Poetry for his work At The End Of The Open Road.

His father was a lawyer of Scottish descent, and his mother Russian. At 17 he emigrated to the United States and began attending Columbia University. During World War II, from 1943 to 1945 he was a member of the 101st Airborne Division and would fight in France, the Netherlands, Belgium, and Germany. After the end of the war he attended the University of Paris.

His first book was The Arrivistes, published in 1949. It was hailed for its strong formal verse, but Simpson later moved away from the style of his early successes and embraced a spare yet obscure brand of free verse. He received a Ph.D. from Columbia and taught there, as well as University of California, Berkeley, and the State University of New York at Stony Brook.