The 103rd Regiment, Ohio Volunteer Infantry was a three-years' infantry regiment from northeastern Ohio that served in the Union Army during the American Civil War. It participated in many of the campaigns and battles of the Army of the Ohio in the Western Theater. The 103rd OVI was organized at Cleveland in August 1862. It was ordered to Kentucky on September 3, 1862, and attached to the 2nd Brigade, 1st Division, Army of Kentucky, Department of the Ohio. The regiment saw action in Kentucky, Georgia, Alabama and Tennessee.