Dmitri Iosifovich Ivanovsky (alternative spelling Dmitrii or Dmitry Iwanowski; Russian: Дми́трий Ио́сифович Ивано́вский; 1864–1920) was a Russian botanist, the first man to discover viruses (1892) and thus one of the founders of virology.Ivanovsky studied at the University of St Petersburg under Andrei Famintsyn in 1887, when he was sent to Ukraine and Bessarabia to investigate a tobacco disease causing great damage to plantations located there at the time.