Major General Harry John Collins (December 7, 1895 – March 8, 1963) was a decorated senior United States Army officer who commanded the 42nd "Rainbow" Infantry Division during World War II.
Collins was born on December 7, 1895, in Chicago, Illinois. He graduated from the Western Military Academy in 1915 and attended the University of Chicago before leaving in 1917 to join the United States Army after American entry into World War I.
Collins completed the course at the Officer Training Camp in Little Rock, Arkansas, in 1917, received his commission as a second lieutenant in the Infantry Branch, and was assigned to the 3rd Infantry Regiment.
Collins served with the 3rd Infantry on the Mexican Border at Eagle Pass, Texas, at the end of the Pancho Villa Expedition and during World War I.
Collins remained with the 3rd Infantry, including assignments at Camp Sherman, Ohio, and Fort Snelling, Minnesota. In 1922, he was assigned to the 19th Infantry Regiment at Schofield Barracks, Hawaii. He completed the Infantry Officer Course at Fort Benning, Georgia in 1926 and remained there as an instructor on the staff of the U.S. Army Infantry School. From 1929 to 1930, he was an instructor at Fort Ethan Allen, Vermont, and he completed the Infantry Advanced Course at Fort Benning in 1930.
A specialist with the placement and marksmanship of machine guns, he operated schools for machine gun operators at Fort Sam Houston, Texas, and Fort Warren in the early 1930s. Collins graduated from the U.S. Army Command and General Staff School in 1934 and the U.S. Army War College in 1935.
He then served again in Hawaii, and in 1938 moved to Vancouver Barracks, Washington, where he was the Plans, Operations and Training Officer (S3) for the 7th Infantry Regiment, and then commanded the regiment's 1st Battalion. After his battalion command he served as regimental executive officer until being assigned as assistant plans, operations and training officer (G3) and then intelligence officer (G2) for the 6th Infantry Division at Fort Snelling.