The 25th Infantry Regiment was an infantry regiment of the United States Army activated in 1866 and deactivated in 1957. One of the "Buffalo Soldier" units, the racially segregated regiment saw action during the American Indian Wars, Spanish–American War, Philippine–American War and World War II.

Buffalo Soldiers were United States Army regiments composed primarily of African Americans, formed during the 19th century to serve on the American frontier. On September 21, 1866, the 10th Cavalry Regiment was formed at Fort Leavenworth, Kansas. The nickname "Buffalo Soldiers" was purportedly given to the regiment by Native Americans who fought against them in the American Indian Wars, and the term eventually became synonymous with all of the African American U.S. Army regiments established in 1866, including the 9th Cavalry Regiment, 10th Cavalry Regiment, 24th Infantry Regiment, 25th Infantry Regiment and 38th Infantry Regiment.