Ilya Ilyich Mechnikov (Russian : Илья́ Ильи́ч Ме́чников, Ukrainian : Ілля Ілліч Мечников) (16 May 1845 – 16 July 1916) was a Russian biologist, zoologist, protozoologist best remembered for his pioneering research into the immune system. Mechnikov received the Nobel Prize in Medicine in 1908, shared with Paul Ehrlich, for his work on phagocytosis. He is also credited by some sources with coining the term gerontology in 1903, for the emerging study of aging and longevity.
Ilya Ilyich Mechnikov was born on May 16, 1845, in a village near Kharkoff in Russia. He was the son of an officer of the Imperial Guard, who was a landowner in the Ukraine steppes. His mother, née Nevakhowitch, was of Jewish origin. In 1867 he returned to Russia, having been appointed docent at the new University of Odessa and from there he went to take up a similar appointment at the University of St. Petersburg. But in 1870 he was appointed Titular Professor of Zoology and Comparative Anatomy at the University of Odessa.