| No. 21 Squadron RAF | |
|---|---|
 | |
| Active | 23 July 1915 – October 1919 December 1935 – November 1947 21 September 1953 – 30 June 1957 1 October 1958 – 15 January 1959 1 May 1959 – 15 September 1967 3 February 1969 – 31 March 1979 |
| Country |  United Kingdom |
| Branch |  Royal Air Force |
| Motto(s) | Latin: Viribus vincimus (By strength we conquer)[1] |
| Insignia | |
| Squadron badge heraldry | A hand erased at the wrist, holding a dumb-bell. The dumb-bell was used as a badge by the squadron in 1917 and symbolises strength. |
No. 21 Squadron of the Royal Air Force was formed in 1915 and was disbanded for the last time in 1979.
The squadron is famous for Operation Jericho on 18 February 1944, when the crews of Mosquitoes breached the walls of a Gestapo prison at Amiens, France, allowing members of the French Resistance to escape.