Nadezhda Konstantinovna Krupskaya (Russian: Надежда Константиновна Кру́пская, 26 February [O.S. 14 February] 1869 – 27 February 1939) was a Russian Bolshevik and the wife of Vladimir Lenin.

Krupskaya was born into a noble family that had descended into poverty, and she developed strong views about improving the lot of the poor. At one Marxist discussion group, she met Lenin who was soon exiled to Siberia, where she was allowed to join him, on condition that they marry. This could suggest a marriage of convenience, though they remained loyal. Following the 1917 Revolution, Krupskaya was at the forefront of the political scene. From 1922–1925, she was aligned with Stalin, Zinoviev and Kamenev against Trotsky's Left Opposition, though she later fell out with Stalin. She was deputy education commissar from 1929 to 1939, with strong influence over the Soviet educational system, including the development of Soviet librarianship.