Nikolay Nikolayevich (Mykola Mykolayovych) Bogolyubov (Russian: Никола́й Никола́евич Боголю́бов; Ukrainian: Микола Миколайович Боголюбов, romanized: Mykola Mykolayovych Bogoliubov; 21 August 1909 – 13 February 1992) was a Soviet, Ukrainian and Russian mathematician and theoretical physicist known for a significant contribution to quantum field theory, classical and quantum statistical mechanics, and the theory of dynamical systems; he was the recipient of the 1992 Dirac Medal for his works and studies.