Corporal Nathaniel M. Allen (April 20, 1840 — July 30, 1900) was a United States soldier who fought in the American Civil War.

His father Gaius Allen, who came from Acton, was a former soldier who served in the Davis Blues Regiment during the War of 1812.

When the civil war broke out on April 12, 1861, he immediately enlisted into the 1st Regiment Massachusetts Volunteer Infantry as a Private, on May 22, 1861, aged 21.

[3] In April 1862, he was promoted to Corporal of the Color Guard and maintained the rank for the rest of his military career.

Whilst retreating, Allen saw Sergeant William Kelren shot and killed - dropping the regimental flag beneath him.