Maria Terwiel (7 June 1910 in Boppard – 5 August 1943 in Berlin-Plötzensee, executed) was a German resistance fighter in the Third Reich. She belonged to the Red Orchestra resistance group.
Her father was a high official in the Pomeranian government, and her mother was Jewish. Maria completed her Abitur at a Gymnasium in Stettin (now Szczecin in Poland) in 1931, after which she studied law in Freiburg (Baden-Württemberg) and Munich. During her studies, she got to know her future fiancé Helmut Himpel, who was a dentist. However, under the Nuremberg Laws, she was deemed to be a "Half-Jewess" ("Halbjüdin"), which meant that the outlook for her getting a job as a junior atttorney (Rechtsreferendarin) was rather grim. After giving up her studies, she went back to her family, who were by now living in Berlin after her father had lost his job in 1933 after the Nazis had come to power. In a German-Swiss textile company, she found a job as a secretary.
The devout Catholic, along with Helmut Himpel, helped Jews in hiding, to whom they furnished identification and ration cards. There arose contacts with the Red Orchestra group about Harro Schulze-Boysen. Terwiel wrote illegal handbills and put up posters against the Nazi propaganda exhibition "Soviet Paradise".
After her arrest on 17 September 1942, Maria Terwiel was sentenced to death on 26 January 1943 by the Reichskriegsgericht ("Reich Military Tribunal"). She was put to death at Plötzensee Prison in Berlin.