Ellison DuRant Smith (August 1, 1864 – November 17, 1944) was an American cotton planter, lobbyist, and Democratic Party politician who represented South Carolina in the United States Senate from 1909 until 1944.

Smith was widely known for his virulently racist and segregationist views, his advocacy of white supremacy, and his support for the Southern cotton industry, earning him the nickname “Cotton Ed”.

Smith was born near Lynchburg, South Carolina, the youngest child of William Hankin Smith and Mary Isabella Smith (née McLeod), at his ancestral home, Tanglewood Plantation (formerly Smith's Grove). Throughout his life, he would reside in Tanglewood. Smith attended the University of South Carolina, where he was a member of the Phi Kappa Psi fraternity, and graduated from Wofford College in 1889.

Smith served in the South Carolina House of Representatives from 1896 to 1900. He was unsuccessful in his bid to become a member of the U.S. House of Representatives in 1900. In 1901, Smith helped organize the Farmer's Protective Association and eventually became one of the principal figures in the formation of the Southern Cotton Association in 1905. Between the years 1905 and 1908, he served as a field agent and general organizer in the cotton protective movement. Smith received the nickname "Cotton Ed" after he declared: "Cotton is king and white is supreme."

Smith was elected to the United States Senate in 1908. He was re-elected five times, although from 1920 until 1944, he had four close elections, with three of them leading to run-off elections because he failed to capture a majority. Smith never won more than 61 percent in Democratic Party primaries during that time. During his time in Congress, he had a goal to “keep the Negroes down and the price of cotton up.” Known for being a reputed showman, Smith would publicly promote this goal by riding to Washington on a wagon-load of cotton waving the banner of white supremacy. He also developed a reputation for having a violent temper while speaking in Congress and would at times stand on his feet and try to get the floor speaker's attention by repeatedly hacking his armchair with a penknife whenever the speaker angered him. Smith was not fond of his fellow Senators and liked to describe the Senate Chamber as "the Cave of the Winds."

Between 1909 and 1933, Smith was regarded as a fairly effective senator, though admittedly not of the first rank. A tireless champion of agriculture, he supported some planks of the Progressive Era, having written a small part of them. He sponsored the Muscle Shoals project, a forerunner to the Tennessee Valley Authority. During this time Smith's policies were "a curious mixture of conservatism and liberalism". He was a loyal supporter of President Woodrow Wilson and his New Freedom agenda especially regarding agriculture supporting the Smith–Lever Act of 1914, Smith–Hughes Act, the Warehouse Act of 1916, Federal Farm Loan Act, and Federal Aid Road Act of 1916. His passage of the Cotton Futures Act earned him the nickname "Cotton" Ed Smith. Smith, however, would not favor legislation he felt would largely diversify the Southern economy, reduce the need for the vast presence of the plantation system in the South, or endanger the old Southern way of life. He also supported the Clayton Act, the Federal Trade Commission, the Underwood tariff, and the Adamson Act. He opposed the Keating–Owen Act which prohibited child labor.

Smith, reflecting the xenophobic views of constituents, sponsored numerous bills restricting immigration culminating in the Immigration Act of 1917 that passed over President Wilson's veto. Smith spoke out in support of the Immigration Act of 1924, which limited emigration from Southern and Eastern Europe and effectively entrapped European Jews in the feverish atmosphere of emergent fascism.

During the First World War he supported most of the war time actions of President Wilson but prevented attempts by the President to impose price controls on cotton. After the war he supported the League of Nations and the Treaty of Versailles.