Louis Bielle-Biarrey was born in La Tronche in the department of Isère,[3] but he is also Reunionese on the side of his mother.[4] He started rugby at the age of five in the city of Seyssins, near Grenoble, in 2008, before continuing and finishing his training at FC Grenoble, at the age of thirteen, from 2016 to 2021.[5]