Kateb was born in Ivry-sur-Seine, France, to an Algerian actor, Malek-Eddine Kateb, and a French nurse. He is a grandnephew of the Algerian writer Kateb Yacine. He grew up and lived in Ivry-sur-Seine, in region of Paris until 2011 after moving to Montreuil. The son of an actor, has been immersed in theater since childhood. At age 12 he decided to also become an actor like his father. He did so by reciting his great uncle's texts, Kateb Yacine.
