Mathilde Friederike Karoline Ludendorff was a German psychiatrist. She was a leading figure in the Völkisch movement known for her unorthodox (esoteric) and conspiratorial ideas. Her third husband was General Erich Ludendorff. Together with Ludendorff, she founded the Bund für Gotteserkenntnis, a small and rather obscure esoterical society of theists, which was banned from 1961 to 1977.

The Völkisch movement was a German ethnic nationalist movement active from the late 19th century through the dissolution of the German Reich in 1945, with remnants in the Federal Republic of Germany afterwards. Erected on the idea of "blood and soil", inspired by the one-body-metaphor, and by the idea of naturally grown communities in unity, it was characterized by organicism, racialism, populism, agrarianism, romantic nationalism and – as a consequence of a growing exclusive and ethnic connotation – by antisemitism from the 1900s onward. Völkisch nationalists generally considered the Jews to be an "alien people" who belonged to a different Volk from the Germans.