Samuel Spencer (March 2, 1847 – November 29, 1906) was an American civil engineer, businessman, and railroad executive. With an education interrupted by service in the Confederate cavalry late in the American Civil War, he completed his education at the University of Georgia and the University of Virginia. Spencer spent his career with railroads, rising through the ranks during the busy growth years of American railroading in the late 19th century. He eventually became president of six railroads, and was a director of at least ten railroads and several banks and other companies.