Shmuel Niger was born Shmuel Ṭsharni on 15 June 1883 in Dukora, a small village in Minsk Governorate, to Zev Volf and Brokhe Tsharni (née Hurwitz).
Niger was a child prodigy, studying Talmud until the age of 17 at yeshivas in Berezin and Minsk.