What is "squadron leader"

n. A rank in the RAF, between that of flight lieutenant and wing commander, equivalent to an army major

Squadron leader (Sqn Ldr in the RAF and PAF; 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. Squadron leader has also been used as a cavalry command appointment (UK) and rank (France) since at least the nineteenth century. In Argentina it is used as a command appointment by both the army's cavalry and by the air force's flying units.

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.

An air force squadron leader ranks above flight lieutenant and immediately below wing commander.The air force rank of squadron leader has a NATO ranking code of OF-3, equivalent to a lieutenant-commander in the Royal Navy or a major in the British Army or the Royal Marines. The equivalent rank in the Women's Auxiliary Air Force, Women's Royal Air Force (until 1968) and Princess Mary's Royal Air Force Nursing Service (until 1980) was "squadron officer".

The cavalry rank of squadron leader in France is also an OF-3 equivalent to a major, and the cavalry appointment of squadron leader in the UK generally corresponds to this rank as well.