A squadron, or naval squadron, is a small formation of large warships that may be part of a larger fleet. A squadron is usually composed of a homogeneous group of the same class of warship, such as battleships or cruisers. Smaller warships are grouped in flotillas. In the US Navy, the term squadron has always been used for formations of destroyers and submarines.

A squadron is usually commanded by a Vice Admiral or a Rear Admiral, but squadrons are sometimes commanded by Commodores or simply the most senior Captain, depending on the importance of the command. A large squadron will sometimes divided into two or more divisions, each of which might be commanded by a subordinate admiral. Like a fleet, a squadron is usually, but not necessarily, a permanent formation.

There are several types of squadron:

• Independent squadrons. In effect, these are formations that are too small to be called a fleet. Independent squadrons may be assigned to and named after a particular ocean or sea, and the admiral commanding the squadron may be the naval commander in chief in that theatre.
• Temporary sub-divisions of a fleet. In the age of sail, fleets were divided into van, centre and rear squadrons, named after each squadron’s place in the line of battle. A temporary detachment from a fleet would also be called a squadron.
  • Permanent battle formations. As warships evolved during the 19th Century, larger warships began to be formed into and trained as permanent, numbered squadrons of the same class of warship such as the 5th Battle Squadron of the Royal Navy's Grand Fleet.

  In modern navies, squadrons have tended to become administrative units. Most navies began to abandon the squadron as a tactical formation during the Second World War. The need to provide capital ships with the anti-submarine protection of a destroyer screen and air cover from an aircraft carrier led to the increasing use of ad hoc task forces, composed of whichever ships were available for a particular operation.

  As warships have grown larger, the term squadron has gradually replaced the term flotilla for formations of destroyers, frigates and submarines in many navies.

  A naval squadron has no direct equivalent on land, but is, perhaps, the rough equivalent in value of an army division.

  Squadrons