Haldimand Sumner Putnam (October 15, 1835 – July 18, 1863) was a brevet colonel in the Union Army during the American Civil War.

Haldimand Putnam enrolled in the West Point Military Academy at the age of sixteen, and graduated in 1857 with high honors.

[3] He immediately joined the United States Army, and was stationed at several points throughout the western frontier.

[3] In 1863, Putnam commanded a brigade in the Stono Inlet expedition as well as in the capture of Morris Island.

However, he had been an acting brigadier general for several months preceding the Second Battle of Fort Wagner, on July 18, 1863.