Sergeant

Sergeant is the fifth enlisted rank (E-5) of the UNSC Marine Corps and the UNSC Army and is a non-commissioned officer. It is equal to the rank of Petty Officer Second Class in the UNSC Navy and Staff Sergeant in the UNSC Air Force. Sergeants in the Army may lead fireteams of around 4 soldiers, while Marine Sergeants typically lead squads of around 12 other Marines.

While Sergeant is a rank on its own, the title 'Sergeant' is often used to refer to any enlisted ranks    of the UNSC Marine Corps or Army which carry the title Sergeant: 

  UNSC Marine Corps

 * Sergeant 
 * Staff Sergeant
 * Gunnery Sergeant
 * First Sergeant
 * Master Sergeant
 * Sergeant Major
 * Master Gunnery Sergeant
 * Sergeant-Major of the Marine Corps

UNSC Army

 * Sergeant
 * Staff Sergeant
 * Sergeant First Class
 * Master Sergeant
 * Sergeant-Major
 * Command Sergeant-Major
 * Sergeant-Major of the Army

Air Force

 * Airman Basic
 * Airman
 * Airman First Class
 * Senior Airman
 * Staff Sergeant
 * Technical Sergeant
 * Master Sergeant
 * Senior Master Sergeant
 * Chief Master Sergeant
 * Command Chief Master Sergeant
 * Chief Master Sergeant of Air Force

Army

 * Private
 * Private First Class
 * Specialist
 * Corporal
 * Sergeant
 * Staff Sergeant
 * Sergeant First Class
 * Master Sergeant
 * First Sergeant
 * Sergeant-Major
 * Command Sergeant-Major
 * Sergeant Major of the Army

Marine Corps

 * Private
 * Private First Class
 * Lance Corporal
 * Corporal
 * Sergeant
 * Staff Sergeant
 * Gunnery Sergeant
 * Master Sergeant
 * First Sergeant
 * Master Gunnery Sergeant
 * Sergeant-Major
 * Sergeant-Major of the Marine Corps

Navy

 * Crewman Recruit
 * Crewman Apprentice
 * Crewman
 * Petty Officer Third Class
 * Petty Officer Second Class
 * Petty Officer First Class
 * Chief Petty Officer
 * Senior Chief Petty Officer
 * Master Chief Petty Officer
 * Command Master Chief Petty Officer
 * Force Master Chief Petty Officer
 * Fleet Master Chief Petty Officer
 * Master Chief Petty Officer of the Navy