Yan Chernyak (6 April 1909 – 19 February 1995) was a World War II era spy who led a network of several dozen people in Germany working for the Soviet Union's military intelligence, the GRU.

[2] Chernyak (alternative Latin-character spelling Czerniak), was born in 1909, in North Bukovina, Austro-Hungarian Empire.

[4] Among the many agents run by Chernyak are said to have been the famous actresses of the Third Reich, Marika Rokk and Olga Chekhova.

[4] Chernyak is credited with "obtaining information used to devise the first Soviet radar, which formed part of Moscow's air defenses during Nazi raids in 1941, according to a statement from the Russian army's general staff.

After World War II, and until retiring in 1969, Chernyak was a translator for the official Soviet news agency, Tass.