James Madison Tuttle (September 24, 1823 – October 24, 1892) was a soldier, businessman, and politician from the state of Iowa who served as a general in the Union Army during the American Civil War. He commanded a brigade and then a division in the Army of the Tennessee in several campaigns in the Western Theater of operations. He led the first Union troops that entered the enemy-held Fort Donelson in 1862, paving the way for the fort's subsequent surrender to Ulysses S. Grant and opening the Cumberland River as an avenue of invasion of the South.