Marianne Katharina "Käthe" Leichter (Vienna, 20 August 1895 – February 1942) was an Austrian economist, women's rights activist, journalist and politician.
She was a member of the Social Democratic Party of Austria and the Viennese Labour Chamber.
She was detained in Ravensbrück concentration camp during the Nazi regime and killed by gas at the Bernburg Euthanasia Centre in 1942.