Manning Marius Kimmel (also known as Marius Manning Kimmel, October 25, 1832 – February 27, 1916) was a military officer who served on both sides of the American Civil War. He entered the United States Military Academy at West Point in 1853 and graduated in 1857. After initially fighting for the Union, he switched sides to the Confederacy, one of four West Point graduates to fight on both sides during the war