Marie Luise Baroness of Münchhausen (27 September 1908 - 6 November 1999), born Baroness of Hammerstein-Equord, was a German lawyer. Despite being born into an aristocratic army family she became an activist member of the Communist Party. She worked for the party's intelligence service during the 1930s. She was treated with on-going suspicion and subjected to a number of interrogations by the security services between 1933 and 1945, although her party intelligence involvement is confirmed only in a document dated 1973.