Otto Johann Maximilian Strasser (also German: Straßer, see ß; 10 September 1897 – 27 August 1974) was a German politician and an early member of the Nazi Party.
Otto Strasser, together with his brother Gregor Strasser, was a leading member of the party's left-wing faction, and broke from the party due to disputes with the dominant "Hitlerite" faction.
He formed the Black Front, a group intended to split the Nazi Party and take it from the grasp of Hitler.
This group also functioned during his exile and World War II as a secret opposition group.
His brand of National Socialism is now known as Strasserism.