William Preston Johnston (January 5, 1831 – July 16, 1899) was a lawyer, scholar, poet, and Confederate soldier. He was the son and biographer of Confederate General Albert Sidney Johnston. He was a president of Louisiana State University and the first president of Tulane University. During the American Civil War, Johnston served as an aide-de-camp to Jefferson Davis, president of the Confederate States. Johnston was a colonel in the Confederate Army. Johnston was captured with Jefferson Davis at Irwinville, Georgia at the end of the war, and was imprisoned for several months at Fort Delaware.