A command sergeant major (CSM) is a non-commissioned rank and position of office in the United States Army.

The holder of this rank and position is the most senior enlisted member of a color-bearing Army unit (battalion or higher).

The exact duties vary depending on the unit commander, including observing training and talking with soldiers and their families.

In contrast, the duties of a sergeant major have been defined in the U.S. Army since the days of von Steuben (1779).

The need for a senior enlisted advisor to a commander was recognized in the Vietnam War era (December 1966).