<!-- thumb|No. 1 Squadron badge -->

thumb|Typhoons representing the RAF Typhoon squadrons – 1 Sqn, 2 Sqn, 3 Sqn, 6 Sqn, 29 Sqn, 11 Sqn, 41 Sqn, 1435 Flight, and BOB75 in the centre to commemorate the Battle of Britain

Squadrons are the main form of flying unit of the Royal Air Force (RAF). These include Royal Flying Corps (RFC) and Royal Naval Air Service (RNAS) squadrons incorporated into the RAF when it was formed on 1 April 1918, during the First World War. Other squadrons of the RAF include those from Commonwealth air forces which have served within the RAF structure and squadrons of the Fleet Air Arm before it transferred to the Royal Navy in 1939.

Some squadrons have an individual tradition of presenting their squadron number in Roman numerals or using a suffix to their squadron number (such as "(F)" for "Fighter", "(B)" for "Bomber" or "(AC)" for "Army Co-operation") to indicate a past or present role. An example would be No. 18 (Bomber) Squadron RAF which currently actually operates the heavy-lift Chinook helicopter. However, these practices have, at least in the past, been deprecated at higher levels and generally only apply to certain squadrons with long traditions, especially those numbered from 1 to 20. Historical Squadrons can choose to 'lay up' their standards at RAF Cranwell or in places of worship following disbandment.

Flying training units and operational evaluation squadrons have generally been (Reserve) squadrons, although they are regular active-duty units. The policy of the (Reserve) numberplate was rescinded in February 2018, to coincide with the renaming of 22 (Training) Group to just 22 Group in line with other RAF Groups.

Some Squadron names include the location they were originally formed.

Regular RFC, RNAS, and RAF squadrons (Nos. 1–299)

Squadrons in Bold Type are currently active

Nos. 1–50

Nos. 51–66

Nos. 67–71

During the First World War, in order to avoid confusion with similarly numbered British flying squadrons, units of the separate Australian Flying Corps were known for administrative purposes as 67, 68, 69, and 71 squadrons. Since the Second World War these numbers have always been used by RAF units.

However, the designation 70 (or LXX) Squadron has always been used for RFC/RAF units.

  • No. 67 Squadron
  • 1916–18: No.&nbsp;1&nbsp;Squadron,&nbsp;Australian&nbsp;Flying&nbsp;Corps
  • From 1941: No. 67 Squadron
  • No. 68 Squadron
  • 1916–18: No.&nbsp;2&nbsp;Squadron,&nbsp;Australian&nbsp;Flying&nbsp;Corps
  • From 1941: No. 68 Squadron
  • No. 69 Squadron RAF
  • 1916–18: No.&nbsp;3&nbsp;Squadron&nbsp;Australian&nbsp;Flying&nbsp;Corps
  • From 1941: No. 69 Squadron
  • No. LXX Squadron (Atlas C1)
  • No. 71 Squadron
  • 1916–18: No.&nbsp;4&nbsp;Squadron&nbsp;Australian&nbsp;Flying&nbsp;Corps
  • From 1940: No. 71 Squadron (staffed by US volunteers in 1940–42)

Nos. 72–100

Nos. 101–150

Nos. 151–200

Nos. 201–250

The first squadrons to carry numbers above 200 were former RNAS squadrons that were renumbered upon amalgamation with 200 added to their RNAS squadron number. Independent flights of the RNAS were grouped together in squadrons and given numbers in the 200 series.

Nos. 251–299

Nos. 300–352

Squadrons in the 300–352 series were staffed during the Second World War by volunteers from countries in occupied Europe. In some cases, these RAF squadrons and personnel were regarded by a relevant government-in-exile as serving concurrently with its air force.

Similarly, in 1940–42, three "Eagle Squadrons" were composed of volunteers from the US: No. 71 (Eagle) Squadron, later 334th Fighter Squadron USAAF; No. 121 (Eagle) Squadron, later 335th Fighter Squadron USAAF and No. 133 (Eagle) Squadron, later 336th Fighter Squadron USAAF.

Polish (300–309)

:See also Squadrons Nos. 315–318, 663 and Polish Fighting Team (under Other)

  • No. 300 "Land of Masovia" Polish Bomber Squadron (Ziemi Mazowieckiej)
  • No. 301 "Land of Pomerania" Polish Bomber Squadron (Ziemi Pomorskiej)
  • No. 302 "City of Poznań" Polish Fighter Squadron (Poznański)
  • No. 303 "Kosciuszko" Polish Fighter Squadron (Warszawski im. Tadeusza Kościuszki)
  • No. 304 "Land of Silesia" Polish Bomber Squadron (Ziemi Śląskiej im. Ks. Józefa Poniatowskiego)
  • No. 305 "Land of Greater Poland" Polish Bomber Squadron (Ziemi Wielkopolskiej im. Marszałka Józefa Piłsudskiego)
  • No. 306 "City of Toruń" Polish Fighter Squadron (Toruński)
  • No. 307 "City of Lwów" Polish Fighter Squadron (Lwowskich Puchaczy)
  • No. 308 "City of Kraków" Polish Fighter Squadron (Krakowski)
  • No. 309 "Land of Czerwień" Polish Fighter-Reconnaissance Squadron (Ziemi Czerwieńskiej)

Czechoslovak (310–313)

(Note: the RAF has never had a flying unit named 314 Squadron, although it has used the number for No. 314 Technical Services Unit. A proposed 314 Squadron was allocated squadron code "UY" during the period April to September 1939, but was never formed.)

Polish (315–318)

:See also Squadrons Nos. 300–309, 663 and Polish Fighting Team (under Other)

Note: the RAF never had a No. 319 Squadron; the "Polish Fighting Team" was attached to No. 145 Fighter Squadron. A proposed 319 Squadron was allocated squadron codes VE for the period April to September 1939. but were allocated Squadron Codes OK, ML and KN respectively for the period April to September 1939. but Squadron codes letters FR were allocated for the period April to September 1939.

Article XV squadrons of World War II (Nos. 400–490)

Under Article XV of the British Commonwealth Air Training Plan, the air forces of Australia, Canada and New Zealand formed squadrons for service under RAF operational control. Most were new formations, however some had already existed prior to the creation of Article XV and had already been operational during the war, including combat operations.

Royal Canadian Air Force (400–443)

Note: Although squadron numbers 444 to 449 were also reserved for the RCAF, it did not use them during the Second World War.

Royal Australian Air Force (450–467)

Note: Although squadron numbers 465 and 468 to 479 were also reserved for the RAAF during the Second World War, it did not use them.

Royal New Zealand Air Force (485–490)

Note: Although the squadron numbers 491 to 499 were reserved for RNZAF units during the Second World War, no such squadrons were formed.

Royal Auxiliary Air Force squadrons (Nos. 500–509)

Formed as "Special Reserve" squadrons but absorbed into the Royal Auxiliary Air Force

Note: No. 505, 506, 507, 508 and 509 Squadrons allocated Squadron codes YF, FS, GX, DY and BQ respectively for the period April to September 1939, but were never formed. In the event the plan was never put into effect, although there was some desultory use of some of the numbers by some of the OTUs for a short period. Despite their lack of formal activation, this block of numbers has never been re-allocated for use by other units.

Advanced Training Squadrons (550–565)

In the event of a German Invasion the Operational Training Units would have been re-formed into the Squadrons below, under plans as part of Operation Saracen, formulated in Spring 1940, which were later revised as Operation Banquet. Some reserve Squadron numbers were used by their respective OTU's during operational tasks until at least May 1944.

  • No. 602 (City of Glasgow) Squadron
  • No. 603 (City of Edinburgh) Squadron
  • No. 604 (County of Middlesex) Squadron
  • No. 605 (County of Warwick) Squadron
  • No. 606 (Chiltern) Squadron
  • No. 607 (County of Durham) Squadron
  • No. 608 (North Riding) Squadron
  • No. 609 (West Riding) Squadron
  • No. 610 (County of Chester) Squadron
  • No. 611 (West Lancashire) Squadron
  • No. 612 (County of Aberdeen) Squadron
  • No. 613 (City of Manchester) Squadron
  • No. 614 (County of Glamorgan) Squadron
  • No. 614A Squadron
  • No. 615 (County of Surrey) Squadron
  • No. 616 (South Yorkshire) Squadron

Note: No. 606 Squadron RAF was allocated Squadron codes BG for the period April to September 1939, but was not formed.

Regular RAF squadrons (Nos. 617–650)