Master Sergeant (MSG) is the eighth enlisted grade (E-8), ranking above sergeant first class and below sergeant major, command sergeant major, Sergeant Major of the Army and equal in grade but not authority to a first sergeant. It is abbreviated as MSG and indicated by three chevrons above three inverted arcs, commonly referred to as "rockers".

A master sergeant may be assigned as a brigade-level section noncommissioned officer in charge and serves as the subject matter expert in his or her field, but may also hold other positions depending on the type of unit. The equivalent-grade first sergeant is the senior noncommissioned officer of a company, battery, or troop.