Otto Hartmann
Otto Hartmann is the name of the following people:
- Otto Hartmann (animal rights activist) (1842–1927), German manufacturer and animal rights activist
- Otto Hartmann (historian) (1858–1908), German historian
- Otto Hartmann (writer) (pseudonym Otto von Tegernsee ; 1876–1930), German authorized signatory, bookseller and writer
- Otto Hartmann (officer) (1884–1952), German general of the artillery
- Otto Hartmann (fighter pilot) (1889–1917), German officer
- Otto Hartmann (politician) (1899 – after 1933), German politician (NSDAP)
- Otto Hartmann (actor) (1904–1994), Austrian actor and informer
- Otto Julius Hartmann (1895–1989), Austrian biologist and natural philosopher
- Otto Karl Hartmann (1882–1945), German insurance lawyer