Joseph A. Sladen (April 9, 1841 - January 25, 1911) was an officer in the United States Army. A Union Army veteran of the American Civil War, he received the Medal of Honor for heroism at the 1864 Battle of Resaca. He continued to serve after the Civil War, and took part in several campaigns of the American Indian Wars. After retiring for disability in 1889, he settled in Portland, Oregon, where he served as clerk of the U.S. Circuit Court. Sladen died in Portland and was buried at West Point Cemetery.