Wilhelm Jahn (2 February 1891 – 21 September 1952) was a German member of the Nazi Party and its paramilitary organization, the Sturmabteilung (SA), who rose to the rank of SA-Obergruppenführer.

At the outset of the First World War, he volunteered for military service with the Imperial German Army and was deployed to the front lines in December 1914 with Foot Artillery Battalion 18.

Typical of many returning German war veterans of this time, Jahn joined right-wing political parties, Wehrverbände (military associations) and völkisch groups.

[5] From 1925 to 1930, Jahn worked as an automobile salesman and sales manager in Osnabrück where he rejoined the local Party on 16 August 1926 (membership number 42,535).

He was then promoted to SA-Gruppenführer and appointed as Chief of Staff of the SA-Obergruppe II in Hanover, overseeing four SA -Gruppe (Niederrhein, Niedersachsen, Nordsee and Westfalen), again under the command of Viktor Lutze.

However, he left the SA on 24 September 1934, after taking a position as a full-time leader of Flieger-Landesgruppe (State Aviation Group) IV of the German Air Sports Association in July.

[9] On 11 January 1939, he was transferred from Halle to Stettin (today, Szczecin) where he took up the duties of Police President and air raid protection coordinator.