
A troop is a
military
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a d ...
sub-subunit, originally a small formation of
cavalry
Historically, cavalry (from the French word ''cavalerie'', itself derived from ''cheval'' meaning "horse") are groups of soldiers or warriors who Horses in warfare, fight mounted on horseback. Until the 20th century, cavalry were the most mob ...
, subordinate to a
squadron. In many armies a troop is the equivalent element to the
infantry
Infantry, or infantryman are a type of soldier who specialize in ground combat, typically fighting dismounted. Historically the term was used to describe foot soldiers, i.e. those who march and fight on foot. In modern usage, the term broadl ...
section or
platoon
A platoon is a Military organization, military unit typically composed of two to four squads, Section (military unit), sections, or patrols. Platoon organization varies depending on the country and the Military branch, branch, but a platoon can ...
. Exceptions are the
US Cavalry and the
King's Troop Royal Horse Artillery where a troop is a subunit comparable to an infantry
company
A company, abbreviated as co., is a Legal personality, legal entity representing an association of legal people, whether Natural person, natural, Juridical person, juridical or a mixture of both, with a specific objective. Company members ...
or
artillery battery. Historically the remainder of the
Royal Horse Artillery used the term ''troop'' in the same manner but they eventually aligned with the rest of the
Royal Regiment of Artillery
The Royal Regiment of Artillery, commonly referred to as the Royal Artillery (RA) and colloquially known as "The Gunners", is one of two regiments that make up the artillery arm of the British Army. The Royal Regiment of Artillery comprises t ...
in referring to troops as subordinate to artillery batteries.
''Troops'' is often used to refer to the other members of one's company or cause, but because of its military connotations, it conveys a particularly altruistic type of dedicated worker. Traditionally, ''troops'' refers to the soldiers in a military.
A cavalry soldier of
private rank is called a "
trooper" in many
Commonwealth armies (abbreviated "Tpr", not to be confused with "trouper").
A related sense of the term, ''troops'' refers to members of the military collectively, as in "the troops"; see
Troop (disambiguation).
Troops in various forces
Today, a troop is defined differently in different armed forces.
In the
Australian Army
The Australian Army is the principal Army, land warfare force of Australia. It is a part of the Australian Defence Force (ADF), along with the Royal Australian Navy and the Royal Australian Air Force. The Army is commanded by the Chief of Army ...
a troop is the equivalent of a platoon sized element in units of certain corps, those being:
*
Australian Army Aviation
*
Royal Australian Armoured Corps
*
Royal Australian Corps of Signals
*
Royal Australian Corps of Transport
*
Royal Australian Engineers
*
Royal Australian Survey Corps (now disbanded)
*
Royal Regiment of Australian Artillery
*
Special Air Service Regiment (SASR)
The SASR is the only unit in the
Royal Australian Infantry Corps to use the term ''troop'' to refer to its platoon-size elements. SASR troops are also unusual as they are commanded by a captain—most troop or platoon-sized elements are commanded by a lieutenant. In most cases, units which refer to platoon sized elements as troops refer to company-sized elements as squadrons and battalion-sized elements as regiments (regiments in the
RAA use the term '
battery' for company-sized elements). Privates in the Royal Australian Armoured Corps and SASR hold the rank "trooper", however this is not the case for any other corps or units, which use the term ''troops''.

In the
British Army
The British Army is the principal Army, land warfare force of the United Kingdom. the British Army comprises 73,847 regular full-time personnel, 4,127 Brigade of Gurkhas, Gurkhas, 25,742 Army Reserve (United Kingdom), volunteer reserve perso ...
the definition of a troop varies by
corps
Corps (; plural ''corps'' ; from French , from the Latin "body") is a term used for several different kinds of organization. A military innovation by Napoleon I, the formation was formally introduced March 1, 1800, when Napoleon ordered Gener ...
.
*
Household Cavalry and
Royal Armoured Corps
The Royal Armoured Corps is the armoured arm of the British Army, that together with the Household Cavalry provides its armour capability, with vehicles such as the Challenger 2 and the Warrior tracked armoured vehicle. It includes most of the Ar ...
: Three or four
armoured fighting vehicle
An armoured fighting vehicle (British English) or armored fighting vehicle (American English) (AFV) is an armed combat vehicle protected by vehicle armour, armour, generally combining operational mobility with Offensive (military), offensive a ...
s commanded by a
subaltern, i.e. effectively the same level element as an infantry platoon. A unit of two to four guns or launchers, or an equivalent headquarters unit.
*
Royal Artillery
The Royal Regiment of Artillery, commonly referred to as the Royal Artillery (RA) and colloquially known as "The Gunners", is one of two regiments that make up the artillery arm of the British Army. The Royal Regiment of Artillery comprises t ...
: A half-battery. In the
Royal Horse Artillery, a troop used to be the equivalent to a battery in other artillery units.
*
Royal Engineers
The Corps of Royal Engineers, usually called the Royal Engineers (RE), and commonly known as the ''Sappers'', is the engineering arm of the British Army. It provides military engineering and other technical support to the British Armed Forces ...
,
Royal Corps of Signals,
Royal Logistic Corps,
Special Air Service
The Special Air Service (SAS) is a special forces unit of the British Army. It was founded as a regiment in 1941 by David Stirling, and in 1950 it was reconstituted as a corps. The unit specialises in a number of roles including counter-terr ...
, and
Honourable Artillery Company (and formerly the
Royal Corps of Transport): A unit equivalent in size to a platoon in other corps, divided into sections or patrols. The Royal Engineers and Royal Corps of Signals used platoons instead until after World War II.
Other Army corps do not use the term.
In the
Royal Marines
The Royal Marines provide the United Kingdom's amphibious warfare, amphibious special operations capable commando force, one of the :Fighting Arms of the Royal Navy, five fighting arms of the Royal Navy, a Company (military unit), company str ...
, a troop is the equivalent to an Army platoon; a carryover from the organisation of the
British Commandos in World War II.
In the
Canadian Army
The Canadian Army () is the command (military formation), command responsible for the operational readiness of the conventional ground forces of the Canadian Armed Forces. It maintains regular forces units at bases across Canada, and is also re ...
, a troop is the equivalent of a platoon within the armoured, artillery, engineer, and signals branches. Two to four troops comprise the main elements of a squadron.
In the
United States Army
The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...
, in the cavalry branch, a troop is the equivalent unit to the infantry company, commanded by a captain and consisting of three or four platoons, and are called a troop within a regiment. Companies were renamed troops in 1883. In some instances, an infantry company may be titled as a "troop" due to its presence in a cavalry squadron; this is typically the case for the
dismounted reconnaissance troop (DRT) of a
RSTA squadron, in which an infantry company-sized element is part of a cavalry-branched squadron.
Troops in civilian organizations
In the United States,
state police forces are often regionally divided into troops. This usage came from these organizations modelling themselves on the US Army, and especially the
older cavalry units. For this same reason the state police and highway patrol personnel of most states are known as "troopers" rather than "officers".
In
Scouting, a
scout troop is a unit made up of scouts or
guides from the same locality under a
leader. In the case of Guides, the term "company" is used more often, and was used by
the founder in his first books about guiding.
References
{{reflist
Military units and formations by size