Thomas Stearns Eliot OM (September 26, 1888 – January 4, 1965) was a publisher, playwright, literary and social critic and "arguably the most important English-language poet of the 20th century." Although he was born an American, he moved to the United Kingdom in 1914 (at age 25) and was naturalised as a British subject in 1927 at age 39.

The poem that made his name, The Love Song of J. Alfred Prufrock—started in 1910 and published in Chicago in 1915—is seen as a masterpiece of the Modernist movement, and was followed by some of the best-known poems in the English language, including Gerontion (1920), The Waste Land (1922), The Hollow Men (1925), Ash Wednesday (1930), and Four Quartets (1945). He is also known for his seven plays, particularly Murder in the Cathedral (1935). He was awarded the Nobel Prize in Literature in 1948.

Eliot was born into the Eliot family, a middle class family originally from New England, who had moved to St. Louis, Missouri. His father, Henry Ware Eliot (1843–1919), was a successful businessman, president and treasurer of the Hydraulic-Press Brick Company in St. Louis. His mother, Charlotte Champe Stearns (1843–1929), wrote poetry and was a social worker, a new profession in the early twentieth century. Eliot was the last of six surviving children; his parents were both 44 years old when he was born. His four sisters were between eleven and nineteen years older; his brother was eight years older. Known to family and friends as Tom, he was the namesake of his maternal grandfather Thomas Stearns.