Joachim Freiherr von Willisen[nb 1] (31 January 1900 – 5 April 1983) was a German public official and member of the Resistance against the Nazi régime.
[2] Willisen became an opponent of the Nazi regime after his uncle Herbert von Bose was murdered in the Night of the Long Knives in 1934.
[3] In 1938 he was transferred to the Reich Ministry of Economics and was conscripted to the Wehrmacht Infantry Regiment 9 in Potsdam in World War II, where he met future participants of the 20 July plot.
Influenced by Fritz-Dietlof von der Schulenburg he became department chief at the Mecklenburg Ministry of State in Schwerin in 1943.
Willisen was arrested on 21 July 1944 after the plot had failed but was released from custody some weeks later because the Gestapo was unable to prove his knowledge about his future role in the plotter's plans.