Lieutenant John R. McNulty (1832 – January 11, 1912) of Baltimore, Maryland was a Confederate soldier. During the Battle of Old Town, his 2nd Maryland Artillery prevented an element of the Army of Northern Virginia led by Brigadier General John McCausland from being trapped behind Union lines. At the time, the unit was returning from raids into Maryland and Pennsylvania, where they had sacked and burned Chambersburg, Pennsylvania. After the civil war, he served as a presidential elector for James A. Garfield in 1881.