The 8th Ohio Infantry Regiment was an Ohian regiment of the Union Army that was active from 1861 to 1864 during the American Civil War. Organized in Cleveland, the regiment earned its reputation as an integral part of the unshakeable "Gibraltar Brigade" at the Battle of Antietam in 1862 and went on to fight at the Battle of Gettysburg, the Battle of the Wilderness, and the Battle of Cold Harbor.