Czeslaw Milosz was born to Weronika and Aleksander Milosz on June 30, 1911, in Szetejnie, Lithuania (then under the domination of the Russian tsarist government). After the outbreak of World War I, Aleksander Milosz was drafted into the Tsar's army, and as a combat engineer he built bridges and fortifications in front-line areas. His wife and son accompanied him in his constant travels about Russia. The family did not return to Lithuania until 1918, whereupon they settled in Wilno (then a part of Poland; also called Vilnius or Vilna).

Milosz graduated from high school in 1929, and in 1930 his first poems were published in Alma Mater Vilnenis, a university magazine. In 1931 he co-founded the Polish avant-garde literary group "Zagary"; his first collection of verse appeared in 1933. That same year he co-edited an Anthology of Social Poetry. In 1934 he earned a degree as Master of Law and traveled to Paris on a fellowship from the National Culture Fund. In 1936 he began working as a literary programmer for Radio Wilno. He was dismissed for his leftist views the following year and, after a trip to Italy, took a job with Polish Radio in Warsaw. He spent most of World War II in Nazi-occupied Warsaw working for underground presses.

After the war, he came to the United States as a diplomat for the Polish communist government, working at the Polish consulate first in New York, then in Washington. In 1950 he was transferred to Paris, and the following year he requested and received political asylum. He spent the next decade in Paris as a freelance writer. In 1953 he published The Captive Mind, and his novel, The Seizure of Power, received the Prix Littéraire European from the Swiss Book Guild. In 1960 he moved to the United States to become a lecturer in Polish literature at the University of California at Berkeley. He later became professor of Slavic languages and literature, a position he still holds. He did not visit Poland again until 1981.

In 1980, Milosz was awarded the Nobel Prize for Literature. His other honors include an award for poetry translations from the Polish P.E.N. Center in Warsaw, a Guggenheim Fellowship, and the Neustadt International Prize for Literature. He has written virtually all of his poems in his native Polish, although his work was banned in Poland until after he won the Nobel Prize. He has also translated the works of other Polish writers into English, and has co-translated his own works with such poets as Robert Hass and Robert Pinsky. His translations into Polish include portions of the Bible (from Hebrew and Greek) and works by Charles Baudelaire, T. S. Eliot, John Milton, William Shakespeare, Simone Weil, and Walt Whitman. He died on August 14, 2004.