Lev Genrikhovich Schnirelmann (also Shnirelman, Shnirel'man; Лев Ге́нрихович Шнирельма́н; 2 January 1905 – 24 September 1938) was a Soviet mathematician who worked on number theory, topology and differential geometry.

Together, they developed the Lusternik–Schnirelmann category, as it is called now, based on the previous work by Henri Poincaré, George David Birkhoff, and Marston Morse.

According to Lev Pontryagin's memoir from 1998, Schnirelmann gassed himself, due to depression brought on by feelings of inability to work at the same high level as earlier in his career.

[3][4] On the other hand, according to an interview Eugene Dynkin gave in 1988, Schnirelman took his own life after the NKVD tried to recruit him as an informer.

The great misfortune of his life was that his lodgings consisted of no more than a wretched furnished room, to which he was ashamed to bring his friends.