Duncan Brown Cooper (April 21, 1844–November 4, 1922) was an American journalist, publisher and Democratic politician. He served in both the Tennessee House of Representatives and in the Tennessee Senate. In 1908, he became involved in a feud with a political opponent and newspaper competitor, Edward W. Carmack. Cooper warned Carmack that if his name appeared again in Carmack's newspaper, The Tennessean, he would retaliate. Cooper and his son did in fact retaliate after Carmack ignored the warning and continued to attack and satirize Cooper. Carmack was shot and killed shortly thereafter.