- This article is about the air force rank. For the francophone army rank sometimes translated as squadron leader, see chef d'escadron.
Squadron leader (Sqn Ldr in the RAF and IAF; SQNLDR in the RAAF and RNZAF, formerly sometimes S/L in all services) is a commissioned rank in the Royal Air Force and the air forces of many countries which have historical British influence. It is also sometimes used as the English translation of an equivalent rank in countries which have a non-English air force-specific rank structure. In these cases a squadron leader ranks above flight lieutenant and immediately below wing commander.
The equivalent rank in the Women's Auxiliary Air Force (WAAF), Women's Royal Air Force (WRAF) (until 1968) and Princess Mary's Royal Air Force Nursing Service (PMRAFNS) (until 1980) was squadron officer.
On 1 April 1918, the newly created RAF adopted its officer rank titles from the British Army, with Royal Naval Air Service lieutenant commanders and Royal Flying Corps majors becoming majors in the RAF. In response to the proposal that the RAF should use its own rank titles, it was suggested that the RAF might use the Royal Navy's officer ranks, with the word "air" inserted before the naval rank title. For example, the rank that later became squadron leader would have been air lieutenant commander. However, the Admiralty objected to this modification of their rank titles. The rank title squadron leader was chosen as squadrons were typically led by RAF majors and the term squadron commander had been used in the Royal Naval Air Service. The rank of squadron leader has been used continuously since 1 August 1919.
RAF usage 
From 1 April 1918 to 31 July 1919, the RAF used the equivalent rank major, which was superseded by squadron leader.
Before the Second World War, a squadron leader commanded a squadron of aircraft. Today, however, a flying squadron is usually commanded by a wing commander, with each of the two flights under a squadron leader. However, ground-operating squadrons which are sub-divisions of a wing are ordinarily commanded by a squadron leader. This includes squadrons of the RAF Regiment and University Air Squadrons.
The rank squadron leader is the first senior officer rank within the RAF.
Insignia and command flag 
The rank insignia consists of a thin blue band on a slightly wider black band between two narrow blue bands on slightly wider black bands. This is worn on both the lower sleeves of the tunic or on the shoulders of the flying suit or the casual uniform.
Squadron leaders are the lowest ranking officers that may fly a command flag. The flag may be depicted on the officer's aircraft or, should the squadron leader be in command, the flag may be flown from a flagpole or displayed on an official car as a car flag. If the squadron leader is in command of a numbered squadron, then the number of the squadron is also shown on the flag.
Other air forces 
The rank of squadron leader is also used in a number of the air forces in the Commonwealth, including the Bangladesh Air Force (BAF), Ghana Air Force, Indian Air Force (IAF), Sri Lanka Air Force (SLAF), Pakistan Air Force (PAF), Royal Australian Air Force (RAAF) and Royal New Zealand Air Force (RNZAF). It is also used in the Egyptian Air Force, Hellenic Air Force, Nigerian Air Force (NAF), Royal Air Force of Oman and the Royal Thai Air Force.
The Royal Canadian Air Force (RCAF) used the rank until the unification of the Canadian Forces in 1968, when army-type rank titles were adopted. Canadian squadron leaders were retitled as majors. In official French Canadian usage, a squadron leader's rank title was commandant d'aviation. The Chilean Air Force equivalent rank, in Chilean Spanish, is comandante de escuadrilla or squadron commander.
An RAAF squadron leader's sleeve/shoulder insignia
A RTAF squadron leader's rank insignia
A PAF squadron-leader's shoulder rank insignia.
Notable squadron leaders 
- Squadron Leader Nikki Thomas, Tornado GR4 navigator of 31 Squadron.
Walter H. Longton - WW1 Flying Ace
Land forces 
In the British Household Cavalry and Royal Armoured Corps, "squadron leader" is the title (but not the rank) often given to the commander of a squadron (company) of armoured fighting vehicles. The squadron leader is usually a major, although in the Second World War the post was often held by a captain.
The rank has been borrowed in science fiction including the Star Wars films and its extended universe of literature and comics, though (at least in the Star Wars franchise) more often as the title and\or callsign of the leader of a starfighter squadron, irrespective of rank (similar to the aforementioned RAC usage; see flight leader), and usually with the word "squadron" replaced by the name of the squadron, e.g. red leader for the commander of Red Squadron, and infrequently as an actual rank. For the most part, this is just another example of common depiction of starfighter forces in most works featuring such craft as closely paralleling contemporary (at the time the work in question was produced) real-world air forces in almost all aspects.
See also 
- "Ranks and Badges of the Royal Air Force". Royal Air Force. 2007. Retrieved 2007-12-01.
- "All-female Tornado jet crew describe war in Afghanistan". The Daily Telegraph. 20 December 2009.
|Commissioned officer ranks of the British Armed Forces|
|NATO rank code||Student Officer||OF-1||OF-2||OF-3||OF-4||OF-5||OF-6
|Royal Navy||O Cdt||Mid||SLt||Lt||Lt Cdr||Cdr||Capt||Cdre||RAdm
|Adm of the Fleet|
|Royal Marines||2Lt||Lt||Capt||Maj||Lt Col||Col||Brig||Maj-Gen||Lt-Gen||Gen
|Army||O Cdt||2Lt||Lt||Capt||Maj||Lt Col||Col||Brig||Maj-Gen||Lt-Gen||Gen
|Royal Air Force||OC / SO||APO / Plt Off||Fg Off||Flt Lt||Sqn Ldr||Wg Cdr||Gp Capt||Air Cdre||AVM||Air Mshl||Air Chf Mshl