The 2nd Maryland Infantry was an American military regiment in the Union Army during the American Civil War. It should not be confused with the 2nd Maryland Infantry, CSA, which was composed of Maryland volunteers who fought for the Confederacy during the war. The regiment fought at numerous battles during the course of the war, and lost 5 officers and 84 men killed and wounded, plus 3 officers and 134 men died of disease, for a total of 226 casualties.