Otto Ludwig Binswanger (/ˈbɪnzwæŋər/; German: [ˈbɪsvaŋɐ]; 14 October 1852 in Scherzingen, Münsterlingen – 15 July 1929 in Kreuzlingen) was a Swiss psychiatrist and neurologist who came from a famous family of physicians; his father was founder of the Kreuzlingen Sanatorium, and he was uncle to Ludwig Binswanger (1881–1966) who was a major figure in the existential psychology movement. He was brother-in-law to physiotherapist Heinrich Averbeck (1844–1889). Other notable family members include his son-in-law Hans-Constantin Paulssen (1892-1984), who was the first president of the BDA (Bundesvereinigung der Deutschen Arbeitgeberverbände) (Confederation of German Employers' Associations).