Osip studied at the University of Paris, gaining a medical degree in 1896.
He married Musia Gershevna in 1899, who had also recently graduated with a medical degree from the Sorbonne.
Gelfond was friends with Anatoly Lunacharsky, Lazar Lagin and Lev Tumarkin.
[1] He participated in a seminar held in St Petersburg in 1908 by the Russian Machists which led to the publication of Studies in the Philosophy of Marxism.
[2][3] He was the father of Alexander Gelfond, born in 1906.