Marianne "Mariandl" Feldhammer (born Marianne Kalss: 14 March 1909 - 15 June 1996) was an Austrian resistance activist during the Nazi years. She was one of the most important women in the (overwhelmingly male) around Sepp Plieseis. She was the only woman who knew the way to the so-called "Hedgehog" (cave-like hut) used by anti-Nazi partisans, to which by the end of the war she had herself made several deliveries of food and/or messages.