23rd Regiment Massachusetts Volunteer Infantry was an infantry regiment in the Union army during the American Civil War. It was formed on 28 September 1861 in Lynnfield, Massachusetts, though some of the men were not mustered until the regiment's arrival to Annapolis, Maryland on 5 December, and comprised 6 companies from Essex County, Massachusetts and 1 each from Bristol, Plymouth, Middlesex and Worcester. An ex-militia officer, John Kurtz, was commissioned its colonel.