Oskar Walther Gerhard Julius Freiherr[a] von Watter (2 September 1861 – 23 August 1939) was a German Generalleutnant who came from an old Pomeranian noble family.

[2] In March 1920, von Watter was in command of military district VII stationed at Münster during lead-up to the Ruhr uprising, an attempt by far left workers to set up a soviet-style council republic in Germany.

The workers responded with a general strike, and on 2 April, the government ordered units of the Reichswehr and Freikorps under the command of von Watter into the Ruhr area.

Von Watter defended himself from other charges that his men had engaged in unlawful behaviour by citing a letter from the Ministry of the Reichswehr that stated, "You are given complete freedom to do what the situation demands".

[3][4] On his initiative, to the south of Horst Castle, in Essen in 1934 a monument was erected in memory of the Freikorps soldiers who died in 1920 during the suppression of the Ruhr uprising.