Platoon sergeant

In many militaries, a platoon sergeant is the senior enlisted member of a platoon, who advises and supports the platoon's commanding officer in leading the unit.

Singapore
In the Singapore Armed Forces, a platoon sergeant serves as the "bridge" between the platoon commander and the rest of the platoon, leading the platoon in many assigned tasks and assuming command in the platoon commander's absence. In some platoons, there may be more than one platoon sergeant.

Platoon sergeants exercise authority over section commanders who are only responsible for the management of a given section in the platoon. Platoon sergeants work with the Company Sergeant Major and subordinate section commanders. They are responsible for the discipline and training of the men. The platoon sergeant is responsible for preparing the men for parades and ceremonies. In exercises and operations, he is in charge of logistics and medical aid.

For NSFs (conscripts), platoon sergeants are selected as third sergeants. They are usually specialists who graduated with a Silver/Gold Bayonet, though it may not often be the case. NSFs who are in active units and who have shown exemplary conduct on and off the field can be recommended to attend the course and take up a NSF Platoon Sergeant Role. On completion of the platoon sergeant course at the School of Infantry Specialists, they will assume their appointments. Promotion to the rank of 2SG will be determined by the parent unit.

For Regulars, they are usually first sergeants. It is a must to have completed their section commander tour before assuming the appointment.

United States
In the United States Army, a platoon sergeant is usually a Sergeant First Class and is the senior enlisted member of the platoon, and is the primary assistant and advisor to the platoon leader (and acts as the platoon leader in his or her absence). Unless the platoon leader has extensive prior experience as an enlisted member before being commissioned as a lieutenant, it is likely that the platoon sergeant will have a greater wealth of military experience due to the disparity in military service length between a new lieutenant and a Sergeant First Class (typically a platoon leader has between one and three years of service, whereas a platoon sergeant has from 7 to 15 years of service). Service experience, however, is not a prerequisite for commissioning and command. On occasion, when a Sergeant First Class is not available, either organically within the platoon or from another unit, a responsible Staff Sergeant will probably be appointed to fill the platoon sergeant position instead. Here is an excerpt from the Army's Field Manual titled "The Army Noncommissioned Officer Guide" (FM 7-22.7).

"'While 'Platoon Sergeant' is a duty position, not a rank, the platoon sergeant is the primary assistant and advisor to the platoon leader, with the responsibility of training and caring for soldiers. The platoon sergeant helps the commander to train the platoon leader and in that regard has an enormous effect on how that young officer perceives NCOs for the rest of his career. The platoon sergeant takes charge of the platoon in the absence of the platoon leader. As the lowest level senior NCO involved in the company METL, platoon sergeants teach collective and individual tasks to soldiers in their squads, crews or equivalent small units.'" In the United States Marine Corps, the billet of platoon sergeant is usually held by a Staff Sergeant (E-6). In 1929 the rank of Platoon Sergeant was officially authorised. World War II the rank of Platoon Sergeant was a "line" grade whilst Staff Sergeant with a bar instead of a "rocker" was a staff grade.