Otto Gleichmann (20 August 1887, in Mainz – 2 November 1963, in Hannover) was a key figure in German expressionism. He produced oil paintings, watercolor paintings, sketches, lithographs and pictures in mixed media.
His works from the 1920s and 1930s were characterised by his bad experiences as a soldier (1915) and his injuries (1916) during the First World War - and his belief that the growth of National Socialism was a bad thing.
He took part in the Hannoversche Sezession from 1918, where he met Kurt Schwitters, among others, and became friends with Theodor Däubler. His exhibition was banned, and he was named a degenerate artist in 1938.