Leonid Fedorovych Toptunov (Ukrainian: Леонід Федорович Топтунов, Russian: Леонид Фёдорович Топтунов; 16 August 1960 – 14 May 1986) was a Soviet engineer who was the senior reactor control chief engineer at the Chernobyl Nuclear Power Plant Reactor Unit 4 on the night of the Chernobyl disaster, 26 April 1986.
