William J. Johnston (July 12, 1850 – September 16, 1941) was a drummer boy in Company D of the 3rd Vermont Infantry during the American Civil War. When his division was routed during the Seven Days Battles during the Peninsula Campaign of June to July 1862, he was the only drummer to come away with his instrument. His superiors considered this a meritorious feat, given that the regiment’s other soldiers had thrown away their guns and equipment to lighten their loads as they retreated. As a result, he received the Medal of Honor in 1863; at age 13, he remains the youngest recipient of the award.