Sarah Aaronsohn was a member of Nili, a ring of Jewish spies working for the British in World War I, and a sister of agronomist Aaron Aaronsohn. She is often referred to as the "heroine of Nili."

NILI was a Jewish espionage network which assisted the United Kingdom in its fight against the Ottoman Empire in the Mutasarrifate of Jerusalem between 1915 and 1917, during World War I. NILI was centered in Zikhron Ya'akov, with branches in Hadera and other Moshava. Nili is an acronym which stands for the Hebrew phrase from the First Book of Samuel: "Netzah Yisrael Lo Yeshaker", which translates as "the Eternal One of Israel will not lie". The British government code-named NILI the "A Organization", according to a 1920 misfiled memorandum in the British National Archives, as described in the book Spies in Palestine by James Srodes.