Ilse Frieda Gertrud Stöbe (17 May 1911 – 22 December 1942) was a German left-wing journalist, Soviet GRU agent and anti-Nazi resistance fighter. As a young woman, Stöbe was exposed to communist ideology through her parents. After her parents split up, she had to leave the Rathaus grammar school she was attending and trained as a typist.

In 1929, wanting to become a journalist, she was employed as a secretary at the Berliner Tageblatt newspaper. There she made deep impression on the editor Theodor Wolff, who wrote a novel about her, "Die Schwimmerin". While there she met the journalist Rudolf Herrnstadt who shared the same communist ideology. In 1931, Herrnstadt recruited Stöbe into the Soviet GRU as a spy. As her career progressed at the newspaper during the early 1930s she visited several countries in Europe to write articles, all the while conducting spying operations for the GRU. Forced to leave Germany in 1933 after losing her job due to the worsening political situation and the rise of Nazism, she first moved to Czechoslovakia. However her face became known after being seen with a Gestapo officer. The GRU then moved her to Warsaw in late 1935. There she worked as the foreign correspondent for the Swiss Neue Zürcher Zeitung newspaper and through them, met a group of left-leaning, liberal anti-nazis who worked at the German embassy. Amongst them was legation councillor Rudolf von Scheliha who supplied intelligence to Stöbe.

In 1939, when the German embassy closed in Warsaw due to the impending German invasion, she moved back to Berlin. There she commanded a Soviet espionage network, while working in the Foreign Office, receiving material from von Scheliha that was delivered to Soviet embassy. When Germany invaded the Soviet Union, she lost contact with Soviet intelligence. Several attempts were made by the GRU to contact her but these failed. Her network was discovered after a Soviet blunder led them to expose her details in a radio message. She was arrested and executed in 1942.

Ilse Stöbe grew up in a working-class home in Berlin. She was the only daughter of carpenter Max Stöbe and his wife Frieda née Schumann. Stöbe had an eight-year-older half-brother from her mother's first marriage, Kurt Müller. The family spent their first year at Mainzer Straße 1 in Lichtenberg, Berlin, before the couple moved to Jungstrasse 14 in Berlin. Both her parents were communist sympathisers but didn't join the Communist Party of Germany (KPD). Her half-brother was radicalised in the area they lived in, which was blighted by poverty and unemployment. It led him to become an active KPD member, taking part in bloody battles between the KPD and the SPD.

There is little information about their youth. However, it is likely she attended the local secondary school located about 3 minutes from her house, before receiving a recommendation to move to grammar school, attending School at the Rathaus [de] in Lichtenberg. At Rathaus, she met her lifelong friend, later publisher and author Helmut Kindler [de]. In 1927, her parents had separated and as a single parent her mother couldn't afford the fees, forcing her to leave in 1927. Her father was no longer mentioned in her letters to her mother, whom she was close to. Stöbe then attended a trade school (Volks- und Handelsschule) to learn a profession as a shorthand typist.

In April 1929, Stöbe began working in the marketing department of the publishing house of the democrat and liberal Rudolf Mosse and then worked as secretary to the journalist, writer Theodor Wolff who was editor-in-chief of the Mosse owned Berliner Tageblatt. Wolff strongly admired Stöbe and promoted her to an editor with her own office close to his. He would eventually write a novel "Die Schwimmerin. Ein Roman aus der Gegenwart" (The Swimmer. A novel from the present) that explores the relationship between bank director Ulrich Faber and his secretary Gerda Rohr. The literary figure of Rohr is based on Stöbe. The novel can best be described as a mood inspired by admiration rather than a description of any concrete events. Wolff's homage to Stöbe and his own reputation guarantees Stöbe's anti-Nazi, proletarian and humanist stance.

At the "Berliner Tageblatt" she met the Jewish editor and communist Rudolf Herrnstadt, eight years her senior and became good friends with him. The couple eventually became engaged. Herrnstadt believed that the political ideology of capitalism with its inherent structural problems in the 1920s, brought on by military defeat, reparations and debt would be replaced by socialism, or indeed communism. From the beginning, Stöbe shared the same political ideology as Herrnstadt. There was an expectation that both of them would join the KPD and several sources state that Stöbe joined the KPD in 1929. However, a study by the German historian Elke Scherstjanoi found that they were told by a KPD official in the Karl Liebknecht house, that they were more useful to the communist party, working outside the KPD. In 1930, when Herrnstadt was a correspondent for the Berliner Tageblatt in Prague, he repeatedly tried to join the communist party. His persistence brought him to the notice of Soviet military intelligence, who recruited him as a Red Army GRU agent and gave him the codename "Arbin".

When Herrnstadt returned to Berlin in 1931, he introduced Stöbe to "Dr. Bosch", who in reality was the Soviet rezident in Berlin, the Latvian Jewish communist and historian Yakov Bronin [ru] (1904–1984). Bronin recruited Stöbe as an agent for the GRU and gradually introduced her to intelligence work. Her codename was "Arnim". From 1931, she worked with Herrnstadt and collected reports that consisted of discussions with Wolff and editorial reports, that were delivered weekly. Being part of an espionage organisation meant clerking duties for Stöbe, e.g. photographing documents, but also involved working in operational tasks like maintaining contact with agents and communist groups in Berlin.