A Staff Sergeant (SSG) is a Non-Commissioned Officer (NCO) in the U.S. Army or Marine Corps (and in other militaries) who is one rank above that of a Sergeant (E5). A Staff Sergeant is responsible for a relatively large number of enlisted servicemembers. Staff Sergeants can often be found as drill sergeants, recruiters, instructors and squad leaders. SSG's have often been in the service for a considerably longer time than standard Sergeants, and have more responsibilities. In fact, a Staff Sergeant usually has several Sergeants working under his direct leadership.

A SSG insignia is characterized by 3 of the standard triangular stripes (chevrons) and a sort of half circle (rocker) at the bottom.

There are also SSGs in the Air Force, but are a pay grade lower, E5. Their insignia is a circled star embedded on 3 chevrons and a close-fitting rocker underneath.

See also: E6, E5, Rank and Pay Grades of the US Military