William G. Bainbridge was the fifth Sergeant Major of the Army, was sworn in on July 1, 1975 and served until June, 1979. He was born in Galesburg, Illinois, on April 17, 1925 and died on November 29, 2008.He entered the Army in June 1943 from Williamsfield, Illinois. He was captured during the Battle of the Bulge.

Sergeant Major Bainbridge was recalled to active duty in January 1951. Following assignments at Camp Atterbury, Indiana, Fort Sheridan, Illinois, Fort Riley, and Fort Leonard Wood, he was reassigned to Europe and served as the Operations Sergeant with Headquarters, VII Corps.

In 1962 he returned to Fort Riley, Kansas, where he served with the 1st Infantry Division as Sergeant Major of the 1st Battle Group, 28th Infantry, late reorganized as the 1st Battalion, 28th Infantry. In 1965 he accompanied the battalion to Vietnam. Midway through his tour in Vietnam, Sergeant Major Bainbridge was appointed Command Sergeant major of the II Field Force.

From September 1966 through August 1967 he was Command Sergeant Major of the U.S. Army Infantry Training Center, Fort Benning, Georgia. He then was appointed the Command Sergeant Major of the First United States Army at Fort George G. Meade, Maryland and later selected to serve as Command Sergeant Major of the United States Army, Pacific located in Fort Shafter, Hawaii.

In October 1972 Sergeant Major Bainbridge became the first Command Sergeant Major of the newly created United States Army Sergeants Major Academy at Fort Bliss, Texas and remained there until his appointment as Sergeant Major of the Army on 1 July 1975.

His awards include the Legion of Merit (3), Bronze Star, Purple Heart (2), Air Medal, Prisoner of War Medal, and the Combat Infantryman Badge.