Staff sergeant

Staff Sergeant is the sixth enlisted rank of the UNSC Marine Corps and the UNSC Army, and the fifth enlisted rank in the UNSC Air Force. It is a staff non-commissioned officer rank. The rank is symbolized by four gold chevrons.

Staff Sergeants typically command squads of 9 - 11 Marines or Soldiers, although they may be selected to become "Platoon Sergeants", which aid the platoon commander. Avery Johnson and Nolan Byrne were platoon leaders on Harvest, and were tasked with training a Colonial Militia, with each responsible for a platoon-sized group of men.

Trivia

 * Compared to other services, the rank of SSgt. in the Air Force is relatively low despite being a position given to flight sergeants.