Nadezhda Nikolaevna Sytinskaya (Russian: Надежда Николаевна Сытинская; 22 February 1906 – 4 July 1974) was a Soviet Astronomer and academic originally from Tallinn who studied meteoroids and planetary surfaces.

[4] At some point after 1934 she was conferred the degree of Doctor of Sciences in Physics and Mathematics by the Soviet Higher Attestation Commission following a successful dissertation defense.

[2] Following the conclusion of World War II, Sytinskaya returned to Leningrad State University where in 1951 she attained an appointment to full professor.

[6] Sytinskaya is credited with, alongside her husband Vsevolod Sharonov, co-formulating the meteor-slag theory of lunar surface regolith formation which hypothesized that the lunar soil was mainly the result of chemical and structural changes to porous surface rock due to meteoroid bombardment vaporizing a thin upper layer into fine dust.

[14] She also introduced the concept of "smoothness factor" as a parameter for determining of the degree of surface roughness exhibited by planetary bodies.