Shershenevich was born in Kazan, Russia on 25 January 1893. He was the son of professor of Law Gabriel Feliksovich Shershenevich, a Polish national and a deputy of the first State Duma from the Constitutional Democratic party and the author of its platform. Shershenevich's mother, Yevgeniya L'vovna Mandel'shtam (L'vova), was an opera singer. At age nine he entered secondary school a year early. After moving with his parents to Moscow in 1907 he studied in the private secondary school of L.I. Polivanov—earlier graduates of the school included Valery Bryusov, Andrey Bely and Sergey Solovyov. After secondary school he began studies in the philological department at Munich University. His studies continued at Moscow University - first in the Department of Law, then in mathematics, in which he took his degree.