John Quincy Marr

John Quincy Marr (May 27, 1825 – June 1, 1861) was a Virginia militia company captain and the first Confederate States Army soldier killed by a Union army soldier in combat during the American Civil War. Marr was killed at the Battle of Fairfax Court House in Fairfax, Virginia, on June 1, 1861.

Previously one of Fauquier County, Virginia's two delegates to the Virginia Secession Convention of 1861, Marr initially opposed Virginia's secession from the Union but ultimately supported it, as did Virginia voters shortly before Marr's fatal skirmish.