Editing Dewoitine D.520 (section)

==Variants==
;D.520
:The main production version, sometimes designated the D.520 S (for ''série'' – production) or the D.520 C1 (for ''chasseur'' – fighter, single-seat).

===Direct derivatives===
In 1940, SNCAM had several projects to fit the D.520 airframe with more powerful engines. These developments were halted by the June armistice.<ref>Belcarz 2005, p. 8.</ref>
;D.521
:engine replaced by a [[Rolls-Royce Merlin]] III, one example was built, but the project was cancelled.
;D.522
:engine replaced by an [[Allison V-1710]] C-1, project abandoned after the armistice (22 June 1940).
;D.523
:engine replaced by slightly different sub-variants of the {{cvt|820|kW}} [[Hispano-Suiza 12Y]]-51, with Szydlowski-Planiol [[supercharger]]. D.523 Prototype was completing pre-production trials in June 1940.
;D.524
:Version powered by [[Hispano-Suiza 12Y|Hispano-Suiza 12Y-89ter]] engine. One prototype built, but it never flew.
;D.525
:development version of the D.523
;D.530
:planned version with a {{cvt|1044|kW}} Rolls-Royce Merlin or a {{cvt|1342|kW}} [[Hispano-Suiza 12Y]].

===Related prewar projects===
;[[Dewoitine HD.780|HD.780]]
:[[Floatplane]] derivative of the D.520, one prototype built, but it never flew, the development was cancelled with the armistice.
;D.790
:Carrier-borne derivative project, none built.
;D.550
:Unarmed aircraft built for speed record attempt, with an airframe loosely based on the D.520, but using weight-saving construction techniques. One example was built.
;D.551 and D.552
:Military developments of the D.550. 12 examples were built, but none flew. The development was resumed in 1941, but was quickly terminated by the Germans.

===Post-armistice developments===
Several projects were initiated after the June 1940 armistice. They were all terminated with the German occupation of Southern France in November 1942.
;D.520 ''amélioré''
:Single production D.520 experimentally fitted with minor improvements to improve top speed with an unchanged engine.
;D.520 Z
:D.520 airframe with 12Z engine and minor improvements. One example was built. The development resumed after the war (as SE.520Z), but was eventually cancelled in 1949.
;M.520 T
:Different airframe loosely based on the D.520. None built.

===Postwar derivative===
;D.520 DC (''double commande'' – dual control)
:Two-seat trainer conversion, at least 13 built.