Leonid Plyushch, Ukrainian mathematician and academic (b. 1938)
Leonid Ivanovych Plyushch (Ukrainian: Леоні́д Іва́нович Плющ, IPA: [ˈplʲuʃtʃ]; Russian: Леони́д Ива́нович Плющ; 26 April 1938, Naryn, Kirghiz SSR – 4 June 2015, Bessèges, France) was a Ukrainian mathematician and Soviet dissident.

Although he was employed to work on Soviet space missions, he became disillusioned with some aspects of the Soviet Union, and started to protest, by sending letters to multiple entities and signing petitions and declarations. These activities led to his interrogation and, in 1972, eventual arrest and imprisonment by the Soviet authorities, where he was injected with drugs and mistreated. He was put on trial in secret, closed to public scrutiny, by the Soviet authorities. Eventually, in 1976, he was able to leave the Soviet Union, and later settled in France, after which he became involved in trying to promote human rights.

In 1979, with the help of his wife, he wrote a book describing how he and other dissidents were placed in psychiatric facilities. Throughout his later years, he supported anti-totalitarian publications.